Installing electric fan need help

[STROKED]

I bought the Derale fan controller part number 16749. They say its designed to run dual fans but comes with 30amp relay, i'm going to run dual fan (4thgen fbody) do i need to add another relay? or replace it with 70-75amp?

Is it ok to split the wire from my gauge temp sender (located on the intake manifold) to the fan controller?

I have 180 Thermostat what temperature do i set the fan to run?

[TnBlkC230WZ]

I bought the Derale fan controller part number 16749. They say its designed to run dual fans but comes with 30amp relay, i'm going to run dual fan (4thgen fbody) do i need to add another relay? or replace it with 70-75amp?

Is it ok to split the wire from my gauge temp sender (located on the intake manifold) to the fan controller?

I have 180 Thermostat what temperature do i set the fan to run?

I looked at it on Summit and it looks like a single controller with a 30/40 Amp relay. It also says for larger dual fans you will need two controllers. Without having the data sheet on that relay you don't know if it is rated at 40 amps max or 40 amps continous. I would personally change the relay to an Omron or DuraKool relay with a 40 amp continous rating (100+ amps surge) and call it good. These will run a Taurus fan on high. If you are running one 15 - 18 amp fan you will be fine with the one that is in there.

as far as temp, where do you want it to run?

[STROKED]

Well i'm going to run 4thgen Fbody dual fan which use's 3 relays that are 30amp from the factory 2 speed Fan operation. 1 relay controlls low speed, and for high speed 2 relays. So i'm guessing i would have to run the same setup? For my setup i just want 1 speed so that would be 2 relay's right? I would like to run both fan's using 1 controller if possible.

The bottom half of this schematic is what referring to. (Late production)
http://shbox.com/1/fan_schematic_1995.jpg

If i set the fan to go off lower than 180 degree's would the thermostat even open?

This is my fan setup
https://static1.pt-content.com/images/pt/2009/12/HPIM1420-1.jpg

[BonzoHansen]

If the controller just trips the relay like fan switch, either use one bigger relay or run 2 regular ones, just split the trigger lead from the controller. I'd run 2 so if one fails I still have some cooling.

To do the 3 relay trick, you need 2 triggers/controllers, one at a lower temp and the other at a higher one.

[TnBlkC230WZ]

Well i'm going to run 4thgen Fbody dual fan which use's 3 relays that are 30amp from the factory 2 speed Fan operation. 1 relay controlls low speed, and for high speed 2 relays. So i'm guessing i would have to run the same setup? For my setup i just want 1 speed so that would be 2 relay's right? I would like to run both fan's using 1 controller if possible.

The bottom half of this schematic is what referring to. (Late production)
http://shbox.com/1/fan_schematic_1995.jpg

If i set the fan to go off lower than 180 degree's would the thermostat even open?


The schematic says the relays are in the under hood electrical center. Most GM electrical centers use Metri-Pack 280 relays which are limited to 35 amps because of the 2.8 MM pins. Get a single Durakool G85B series relay. It is rated at 60 amps continous and 120 amps inrush. It will run the high side.



Another thing about GMs wiring. Relay 3 only serves to wire the fans in series. It doesn't add any power. When the low speed is on, both fans are spinning. When relay's two and three are turned on, fan one gets its ground through relay 3 and both fans get full power. When low speed is on, the fans are wired in series and fan one gounds through fan 2.

The Dakota digital controller will control both fans with you eletrical temp gauge sending unit.

Also, I like that fan setup. What are the actual dimensions?

[STROKED]

I was hopping to avoid having to buy another controller i'm on a budget looks like the Dakota digital controller is pricey. The controller i have lets me remove the relay if i were to put a bigger relay that gets 60amps continuously and 120amp spike, would that work?

Here is the dimension, i'm using the Summitracing radiator and to fit them i pretty much just cut the edges of the fan shroud till i was able to line them up to the radiator. Here is the measurement i took from the fan after cutting it.

5.5 inch from fan shroud to the back of the fan motor
18 inch from the top to the bottom
27 inch across the whole unit

[TnBlkC230WZ]

Yes, that one relay shouls work. They are available from www.newark.com (http://www.newark.com) for about $6. You have to look closely at the one you select. They have surface mount, diodes, hoods and lots of options.

[STROKED]

Looks like a good website, but im having hard time understanding all those options. I tried to go threw there search option and was totally lost because of not knowing what those options on the relays are. Would you be able to suggest one or tell me which one to get.

SPDT or SPST-NO
80A or 100A

ill be plugging it into this harness (what fuse do you recommend. Has a 25amp fuse right now.)

https://static1.pt-content.com/images/pt/2009/12/HPIM1451-1.jpg

[H2Ogbodies]

I pm'd you about some pics you need to check out from installs I've done. I use the Mark VIII fans and they fit that radiator dimension like a glove-I also have a really simple harness kit using a SPDT relay controlling two SPST 70-amp relays, two temp sensors and related wiring. Basically the two temp sensors (different ranges) serve to trigger the fans via the appropriate temp and you can add an over-ride or AC trigger by tying the ground circuit of the clutch coil in with the ground lead to the high speed relay. I have diagrams drawn up and it's super easy to install....with the temp switches and relays, you have two temperature ranges to work with....so either the low speed will be on or off but never at the same time for a dual speed fan and these harnesses will also work with dual fans though a single large fan is always more efficient than any dual fan setup. You don't want cheap relays and you don't want to use crappy parts store wiring. I build quite a few of these so if you need any help, let me know. I've tried every controller there is and while some work better than others, relay activations always work...and replacement parts are a breeze...which is something else to consider.

[85GPLEf41]

I pm'd you about some pics you need to check out from installs I've done. I use the Mark VIII fans and they fit that radiator dimension like a glove-I also have a really simple harness kit using a SPDT relay controlling two SPST 70-amp relays, two temp sensors and related wiring. Basically the two temp sensors (different ranges) serve to trigger the fans via the appropriate temp and you can add an over-ride or AC trigger by tying the ground circuit of the clutch coil in with the ground lead to the high speed relay. I have diagrams drawn up and it's super easy to install....with the temp switches and relays, you have two temperature ranges to work with....so either the low speed will be on or off but never at the same time for a dual speed fan and these harnesses will also work with dual fans though a single large fan is always more efficient than any dual fan setup. You don't want cheap relays and you don't want to use crappy parts store wiring. I build quite a few of these so if you need any help, let me know. I've tried every controller there is and while some work better than others, relay activations always work...and replacement parts are a breeze...which is something else to consider.

Would something like this work on the Intrepid Ramcharger fans? I have some most of the required parts such as relays, circuit breakers, wiring etc etc. What switches do you use for this set up? I tried the parts stores but they just wanted to sell me kits. I would like to try to wire something up on my own. :)

[TnBlkC230WZ]

Looks like a good website, but im having hard time understanding all those options. I tried to go threw there search option and was totally lost because of not knowing what those options on the relays are. Would you be able to suggest one or tell me which one to get.

SPDT or SPST-NO
80A or 100A

ill be plugging it into this harness (what fuse do you recommend. Has a 25amp fuse right now.)


Either will work. SPDT = single pole double throw. It will have five pins. SPST = Single pole single throw. It iwll have four pins. The SPST-NO = single pole single throw-normally open.

The NO position equates to off in most relays and the NC (normally closed) equates to the on position of the relay.

The SPDT relay will have a NO (Normally Open Pin) pin (87a) It is very rare that this pin is used. It will have power when the relay is off.

The dg85c/d relays use a 3/8 pin so they will not fit your controller.

This is the one I used. It has a diode so you have to correctly wire pins 85 and 86 for ground and power

http://www.newark.com/durakool/dg85b-8021-76-1012-dr/automotive-relay/dp/30M9184

This one has a metal bracket, but no diode so you can wire pins 85 and 86 for ground or power. http://www.newark.com/durakool/dg85b-8021-76-1012-dr/automotive-relay/dp/30M9184

[H2Ogbodies]

What year Intrepid fans do you have? 1997-older have bearing issues and that is the reason they were dumped at dirt prices. I know they fit the g-body radiators well but they have a weak motor design besides the bearing issue. 1998-up are better but still feature pancake motor design, not ideal imo. The three relay setup I use is for a single fan, dual speed such as the Mark VIII, Tuarus, T-Bird, etc. For dual fans like the LT1 or LS1, you would need 4 relays for low, high and tandem/AC/over-ride operation. I would need to draw up a quick diagram to be sure...I had one on my desktop but I can't find it-I need to go through my electrical folder and I'll post it up here...

[85GPLEf41]

What year Intrepid fans do you have? 1997-older have bearing issues and that is the reason they were dumped at dirt prices. I know they fit the g-body radiators well but they have a weak motor design besides the bearing issue. 1998-up are better but still feature pancake motor design, not ideal imo. The three relay setup I use is for a single fan, dual speed such as the Mark VIII, Tuarus, T-Bird, etc. For dual fans like the LT1 or LS1, you would need 4 relays for low, high and tandem/AC/over-ride operation. I would need to draw up a quick diagram to be sure...I had one on my desktop but I can't find it-I need to go through my electrical folder and I'll post it up here...

My fans are from a 98 intrepid. I am still trying to come up with a decent diagram including relays, temp switches etc etc

[86Cutlass383SR]

For dual fans like the LT1 or LS1, you would need 4 relays for low, high and tandem/AC/over-ride operation. I would need to draw up a quick diagram to be sure...I had one on my desktop but I can't find it-I need to go through my electrical folder and I'll post it up here...

Please do. I'm running the 88-89 f-body dual fans and I can't find a good schematic to wire mine up. Are these f-body dual fans single speed or 2 speed? I've had them wire up but wasn't real happy with how I had mine. I am using a Howell TPI harness but it doesn't incorporate the electric fans the way the factory does. A write-up on ThirdGen.org says to disconnect control from the ecm for better control anyway. I used a seperate Howell dual fan harness but wasn't really satisfied with it. It was basically one fan hooked to the head temp sensor and another wired into the a/c. Basically two seperate fan systems in one. I'd like them to work together like they're supposed to. Primary fan comes on and then the secondary comes on for additional cooling if needed. Then when you turn on the a/c it turns the fan(s) on. I'd like not to have to remember to turn them off/on.

[MonzaRacer]

I use the Oval GM relays those are some of the toughest I have ever used.
I have the part numbers in my other phone Ill post up the connectors and relays later, but I used to get them from junkyard with plugs for 10 buck a handful, which usually was 6 or 8.

[H2Ogbodies]

Ideally, I run two temp sensors so that the low temp one acts as the primary and is ground-relay controlled while the second temp sensor also is ground-relay activated but is also tied into the AC system. You can easily integrate an over-ride control in parallel.

[85GPLEf41]

I went to some auto part stores and they just kept trying to sell me the kits. What type of senders do you recommend? The ones i have seen online either have 1 or 2 terminals.The with a single terminal are ground activated right? Would you happen to have any part numbers? I hooked up my fans to 12volts and they are dual speed. Since i don't have a/c right now i was thinking both a high and low with maybe a manual override. Thanks

[H2Ogbodies]

I'll check for ya-youneed single spade temp switches, not sensors which complete a path to ground at a specific temp range. If you are running a computer, it doesn't matter what you "want" to run since the ECM needs to see the correct range for operation in closed loop. If this is a carb setup then it doesn't matter. Typically, I run the low range around 190 on/175 off and a high of 215 on/200 off. For various differneces in cooling system efficiencies, you need to allow for a span of +/-10 degrees between the two temp switch values. Plus, to avoid running the fans at freeway speeds, I would suggest plumbing both temp switches in the lower water pump inlet-this way, the coolant temp is maintained by the actual temp coming into the motor-who cares what the temp is leaving as long as the inlet temp is where you want it. This way, at higher sustained speeds, the air rushing through the radiator will keep the temps low enough that the fans will rarely come on. This is how you avoid having the fans coming on when you don't want them to. I'll look up the temp switches I use and post them here.

[TnBlkC230WZ]

I care what temp the water is coming out. The water coming in doesn't warp your heads, the hot water coming out does. The water coming in doesn't maintain your oil temps, the water coming out does. I don't care how cold the water coming in is. If the water coming out is too hot, then the water coming in is still not cold enough.

[H2Ogbodies]

Well...let's think about this for a minute...assuming you have no mechanical problems with your cooling system, you should see an average of 30 degrees or so between the incoming coolant and how much heat the engine builds up during normal combustion. Now, your temp. gauge will tell you what temperature your coolant is at, usually in the intake area, and that is regulated by the thermostat. IF your engine requires additional cooling @ idle or at part throttle cruising (ie city driving) then the incoming low temp sensor will see an increase in temperature and depending on the efficiency of your radiator, you will have a hotter coolant temp on the outlet but it won't be enough to even worry about. The slight increase in coolant temps prior to the fan coming on with low speed is insignificant-we're talking 10-15 degrees, and a slightly warmer engine is better than a slightly cool one-emissions output and thermal efficientcy prove that. It is imo pointless when using relays to trigger electric fans, that you place the sensor switch ground location ahead of the radiator instead of after it-downstream if you will. By placing the temp switch closer to the engine inlet you get a more accurate reading and better relay/fan control. And by using a slightly higher volume water pump, coolant bypass, etc. you can move the coolant out of the engine much more quickly anyway. This idea is two sides of the same coin if you will but I do it with relay triggered fans in mind.

[85GPLEf41]

So mounting the temp switches on the inlet of the water pump would work best?? Sorry but i thought on the head or the intake manifold would work best. How would i install them on a SBC water pump inlet?

[TnBlkC230WZ]

You mention normal engine load. If the engine operated in the same environment all the time, then I would agree. It wouldn't mater where you put the sensor.

I also agree that it is best to run the engine a little warmer. It also helps to evaporate contaminates off of the oil.

However, most street driven engines operate in a wide operating range. Ambient temps can vary by 100 degrees, loads can range from rolling down hill to high speed freeway driving with a fully loaded car and the AC running. If you engine temps start pushing 230 or 240 you need to back off a little. If you are measuring the cold water coming in, you can only estimate the actual engine temps and thats assuming the radiator and water pump are working correctly. If the water pump starts pumping less (loose impeller?), then you estimate will be way off.

[H2Ogbodies]

I understand where you are coming from...my point is that any street engine is only going to build what amounts to 30 degrees of heat give or take a few degrees during its combustion cycle-now, if you know what the temp is leaving by way of an intake temp sensor for the gauge and exiting the engine via the t-stat-say 200 in this case, then if you had your fan switch in the intake, it would be triggered to come on prematurely because you have not allowed enough time for airflow to remove heat from the radiator-and by this I am talking about highway speeds. With proper shrouding, your fan should not have to come on-the inlet temps should drop by at least 30-40 degrees so then the combustion cycle would increase by 30 degrees or so again and be leaving the engine at 190-200 again. If the coolant exiting the t-stat is so high that it runs the risk of engine damage, imo you have a mechanical failure somewhere in the system. Knowing that the amount of heat the engine builds up during combustion is relatively constant even under light loads, it is better to maintain a steady incoming temperature-the engine stays within a narrow temp range which improves thermal efficiency, increase mileage and allows for a more extended electric fan life since it has to cycle on/off much less. Simply drilling/tapping the water pump arm is all that you need to due to add a sensor or two-just be careful of belt interference. I have found it pretty easy to do and avoid any belt problems. I've done this mod often enough to know that it allows you to run a stable engine temperature no matter what the driving conditions are. This was my solution to the fan always kicking on and off on the freeway-this way, i eliminate that problem and it runs much better. Btw, I'll check on those Delphi numbers you pm'd me about-I dont see why I can't get them...I'll get back to you.

[MonzaRacer]

Putting the temp sensor in odd places is pointless, after 20 plus years of building cars, installing salvage yard fans and different controlers I simply see people using overly expensive controlers, trying to reinvent the wheel so to speak.
What your trying to do with a cooling system is maintain a steady temp, which is controled by air flow over the radiator AND fan on/off time to help it maintain thwt at low speeds.
I used the simple thermostatic controlers slide the temp bulb in up near the upper hose of std flow and lower hose on reverse flow (depending where you have the hot side coming in). and never have had issues EXCEPT when I had a fan/shroud I got at a swap meet, wound up removing the crap shroud later on.
As for heat and damage yopu would be surprised what these engines can handle with little or no issues.
I also quit trying to run engines in the 140-160 range, its just not worth the hassle.
If your cooling system is done right, and you have good air flow both at slow speed and at hwy speed your not gonna have issues.
Another great tool for cooling systems I have been selling is Evans Coolings NPG line of coolant, boiling point a like 375degrees, with no pressure, no corrosion as it has zero water, and freeze point as low as 70 below.
Most people are going to large tube aluminum radiators so the NPGR or NPG+ work well, and they sell application specific pumps too.
My big block 402 was cooled by a single fan from a Cavalier, shroud and all, and all with a 3 core Chevelle radiator and usually ran either 180 or 195 thermostats.
My car never ran over 220 and that was in standing traffic, and had idled in gear for long time (did have trans going out and this was with week old big block) that engine has over 100k and is sitting under tarp waiting till I can drop it in my 84 Caprice.
I never saw creep from that cooling system but that once.
My 77 Monza had a small rad, got my 355 and it never ran over 210 max and had that fan that had the crap shroud i took off.
Only heat issue that car EVER had was one day I went to drag strip and I had some vapor lock issues.
And that was with factory Monza V8, 3 row radiator, VERY small.
I actually used my Intellitronics temp gauge that had a fan out put to control the fan, ran that to a relay.
I see guys spending incredible amounts and just dont have major heat issues on cars.
Since I have found a decent 31x19 all aluminum rad for cheap, I figure the Caprice wont get hot and I have 2 fans from a 90 Grand Prix with no shroud, they will just sit behind the rad, no shroud, leaving it clean between the rad, fans and engine, Iam also looking into a very larger condenser to reinstall the AC.
I will wire the main fan to run when I want, then use the second to come on at a point higher than the first but not hot enough to hurt the engine, and then both will turned on for AC use.
As for having fans kick on and off going down the roadI rarely see it any system I have built, heck I have used the Hyper tech fan switches for sbc that go in the heads like on 80s Camaro.
But the simple adjustables seem to work just fine when hooked up to the relays.
The stock GMs usually come in around 215-230, and off in the 195-200 range, works great.
Keeping an engine in/around the 200 range help on wear, makes more power for street cars, and besides it never has hurt my power making issues except that once.

[TnBlkC230WZ]

H20,

Excellent explanation. I'm just the paranoid type and try to build things to accommodate failure. My paranoia drove me to GXL wire instead of TXL wire in rewire. Given I only have one temp sensor that controls my gauge and hi & low fan, I put it in the manifold to monitor exit temps. I will have a second sensor connected to a warning light mounted in the head.

MonzaRacer,

I'll have to look up the Evans coolant.

[STROKED]

Just got back from holiday with family, started to work on my car again and have few more questions after reading the reply's.

Would it be ok to run coolant sensor/switch at the T-stat housing?
Whats a good coolant temperature gauge I should buy?

I decided to run just single fan speed on my setup, besides the fan life being short any other negative reason for doing this?

[TnBlkC230WZ]

Mine's in the manifold near the t-stat housing. Any of the name brand gauges should be fine. I recommend an electric gauge.

[STROKED]

Either will work. SPDT = single pole double throw. It will have five pins. SPST = Single pole single throw. It iwll have four pins. The SPST-NO = single pole single throw-normally open.

The NO position equates to off in most relays and the NC (normally closed) equates to the on position of the relay.

The SPDT relay will have a NO (Normally Open Pin) pin (87a) It is very rare that this pin is used. It will have power when the relay is off.

The dg85c/d relays use a 3/8 pin so they will not fit your controller.

This is the one I used. It has a diode so you have to correctly wire pins 85 and 86 for ground and power

http://www.newark.com/durakool/dg85b-8021-76-1012-dr/automotive-relay/dp/30M9184

This one has a metal bracket, but no diode so you can wire pins 85 and 86 for ground or power. http://www.newark.com/durakool/dg85b-8021-76-1012-dr/automotive-relay/dp/30M9184

Both of the links appear to be the same, can you get the link for the one with the metal bracket no diode. Thanks

by the way the DG85B's will fit my controller right?
What determines if i need SPST-NO, or SPDT?

[pritchard1970]

I would run two controllers, with my Spal fans I run two so if one goes down I still have the other fan working....We noticed a while back that only one fan was working and it turned out that one of the wires was loose on a controller causing the problem...easy fix and it was back...hope this helps

[TnBlkC230WZ]

Both of the links appear to be the same, can you get the link for the one with the metal bracket no diode. Thanks

by the way the DG85B's will fit my controller right?
What determines if i need SPST-NO, or SPDT?

This one does not have a resistor or diode. Straight metal bracket
http://www.newark.com/durakool/dg85b-8011-96-1012-m1/automotive-relay/dp/30M9185

This one has a resistor, no diode and straight metal bracket
http://www.newark.com/durakool/dg85b-8011-96-1012-m1r/automotive-relay/dp/30M9199

As long as your controller will hold a 5 pin relay with 1/4 inch blades, an SPDT will work. They are sometimes refered to in metric dimensions 6.3 mm. Most SPDT relays are NO, they just don't state it. NO = Normally Open = Off. Off is when the #30 and #87 pin are not connected. I perfer the the SPST relays because they often have a higher rating. It is rare that I need the 87a pin. I like the relays with diodes, you just have to keep up with pin 85 and 86 and know which one is the ground. On none-diode relays it doesn't matter.

This is my prefered relay. It is an SPST with straight metal bracket, no diode.
http://www.newark.com/durakool/dg85b-8021-96-1012-m1/automotive-relay/dp/30M9198

[85GPLEf41]

So does anybody have any temp switch part numbers that may work? I would at least want to run the low speed for now. I have been looking but am confused on how to wire dual fans with dual relays and one temp switch???:confused: any ideas.... I already have the green relays that i pulled out of a Chrysler "something".

[nullshine]

There's a few in here (some kits listed too, but several individual thread-in ones as well).
http://www.summitracing.com/search/Department/Cooling-Heating/Part-Type/Fan-Switches-Thermal/Sending-Unit-Style/Thread-in/?Ns=Rank|Asc (http://www.summitracing.com/search/Department/Cooling-Heating/Part-Type/Fan-Switches-Thermal/Sending-Unit-Style/Thread-in/?Ns=Rank%7CAsc)

GM 3053190 is one from a Grand National, I think it's 210 ON, 200 OFF. (EDIT: More like 203 ON)
I believe that # is discontinued, but you should be able to cross-ref it at an auto parts store.

[TnBlkC230WZ]

So does anybody have any temp switch part numbers that may work? I would at least want to run the low speed for now. I have been looking but am confused on how to wire dual fans with dual relays and one temp switch???:confused: any ideas.... I already have the green relays that i pulled out of a Chrysler "something".

There are a few ways. The only one I found that would read an engine mounted temp switch is the Dakota Digital controller. It works very well and uses it's own switch or can read the electric sender from most any name brand temp gaugae. Mine is hooked to an autometer sensor. It's only down side is it has to be in a dry environment. I started with it inside the car, but have now mounted it in a NEMA 4X rated box and put it under the hood.

It is in the putty colored box
https://static1.pt-content.com/images/pt/2010/01/IMG_0231-1.jpg

[85GPLEf41]

There's a few in here (some kits listed too, but several individual thread-in ones as well).
http://www.summitracing.com/search/Department/Cooling-Heating/Part-Type/Fan-Switches-Thermal/Sending-Unit-Style/Thread-in/?Ns=Rank|Asc (http://www.summitracing.com/search/Department/Cooling-Heating/Part-Type/Fan-Switches-Thermal/Sending-Unit-Style/Thread-in/?Ns=Rank%7CAsc)

GM 3053190 is one from a Grand National, I think it's 210 ON, 200 OFF.
I believe that # is discontinued, but you should be able to cross-ref it at an auto parts store.


Thanks! i will try and see what i can cross reference it with. Is it a 1 or 2 spade? Is that a good temp to run a SBC efficiently? BTW thanks for helping me too @ GBody forum too.:)
TnBlkC230wz i like that controller but its a little over priced for my low budget build. lol I also want to wire it as simple as possible using parts that can be easily replaced from a autoparts store.

[nullshine]

Thanks! i will try and see what i can cross reference it with. Is it a 1 or 2 spade?

That is a single terminal, but from what I remember it uses a somewhat special terminal (not just a regular spade). The connector pig tails should be readily available. It's kind of like a bullet connector, if you know what I mean.

Napaonline cross-refs 3053190 to an Echlin brand switch:
Switch: FS113
http://www.napaonline.com/Search/Detail.aspx?R=ECHFS113_0217662982

Connector pig tail: FSC10
http://www.napaonline.com/Search/Detail.aspx?R=ECHFSC10_0252408144

Hopefully this fits the bill.


Is that a good temp to run a SBC efficiently?

To be 100% honest, I'm no engine guru. It seems to me that your average SBC has a 195° F thermostat. This tells me that the thermostat will keep the engine at 195° most of the time. The fans are only there if the rad can't do that, due to insufficient air flow, so if your temps get to be around 210°, this means the thermostat/rad ain't doin' it, and the rad needs more air.

I don't think that 210° F is too hot. I believe that some of the 3rd Gen F-body guys use this "Grand National" switch to lower their fan turn-on temps, which I _think_ were something in the order of 225° F???? Not sure on that. I know they do use it as a cooler fan switch though. My logic here is that if it's a cooler fan switch than a SBC in a stock F-body, it shouldn't be too hot. If your thermostat opens at 195°, this will typically regulate engine temps to 195°, so 210° shouldn't be too cold. So if it's not too hot, and it's not too cold, it at least won't damage anything. As far as engine temperature vs. max efficiency goes... I don't know. The way I see it, you'd need to change your thermostat to really affect the temperature of your engine. That's my convoluted logic anyhow.


BTW thanks for helping me too @ GBody forum too.:)


You're welcome! Anytime.

[TnBlkC230WZ]

210 on is not too high, but I wouldn't want it any hotter than that. The factory turns them on betweek 210 and 220.

[nullshine]

Hrm, now that I'm digging around a bit, I'm finding some information suggesting that the 3053190 switch may be more around 203° F on.
Different people are reporting seeing different temperatures with it, I'm assuming due to different install locations and variations in the accuracy of switches between brands (and accuracy of temp gauges).

This makes me wonder what the off setting is. Hopefully not too low that it'll run all the time with a 195° F thermostat.

If you decide to go with one, let us know how it works out. Yes, you are now being used as a guinea pig! :idea:

[MonzaRacer]

You can source some lower degree grounding switches from Hypertech and others.
I use what ever I can find from NAPA sensor books that have proper temp ranges and right threads or can be adapted.
As for GM temps it depends, some cars go all the way up to 231 to turn on, others are computer controlled and come on as low as 210.
As for temps the radiator works by air flow, no other thing cools like volumes of air. Hence we have fans.
Again if you need more cooling try looking at this company, the products are top notch bar none: www.evanscooling.com.
The NPG+ would be ideal for pretty much everyone on here as most of us are going with large tube aluminum radiators.

[85GPLEf41]

Hrm, now that I'm digging around a bit, I'm finding some information suggesting that the 3053190 switch may be more around 203° F on.
Different people are reporting seeing different temperatures with it, I'm assuming due to different install locations and variations in the accuracy of switches between brands (and accuracy of temp gauges).

This makes me wonder what the off setting is. Hopefully not too low that it'll run all the time with a 195° F thermostat.

If you decide to go with one, let us know how it works out. Yes, you are now being used as a guinea pig! :idea:

That's cool thanks for the part numbers i will try to get one this week from Napa i can get parts at jobber prices. I hopefully will get it done this weekend if the weather cooperates.

[STROKED]

First time wiring all this up myself, is it alright to tap into positive coil wire for my igntion feed on my cooling fan controller?

[H2Ogbodies]

No. Get a 12V junction block from any junkyard S-10 oe other similar GM vehicle and run an IGN lead wire from your fuse block to one side of it. Now you can use it for any IGN sourced turn on lead you need. It is not a good idea to tap into the 12V lead to your coil. The coil lead should remain an isolated circuit. It comes directly from the fuse panel 12V BATT buse bar and remains hot at all times.

[STROKED]

No. Get a 12V junction block from any junkyard S-10 oe other similar GM vehicle and run an IGN lead wire from your fuse block to one side of it. Now you can use it for any IGN sourced turn on lead you need. It is not a good idea to tap into the 12V lead to your coil. The coil lead should remain an isolated circuit. It comes directly from the fuse panel 12V BATT buse bar and remains hot at all times.

Thanks ill try run a different ignition source wire.

BTW: do you mean just the junction block with out the wiring or the whole wiring and the junction block?

[85GPLEf41]

I just finished up my rough wiring my dual fans using Echlin switch part number ech fs113 for my low speed. I installed it on the t-stat housing. Using my factory gauge it turns the fans on around 218 or so. the temp was cool and i didn't drive it because of the front rebuild. The fans stay on for about a 60-90 seconds. Is this ok? before this the temp needle wouldn't go past 1/4 on the dial.... I am using my factory t-stat.

[H2Ogbodies]

The factory gauge (if that's what you're reading) is almost surely a little off a little on the reading. Sounds like you are running a 220 on 205 off switch. I would look for a slightly lower on/off temp switch. On the junction block question, if you notice, they have a metal tab which has usually two 10-gauge wire leads factory crimped to one end of the tab. You can either carefully pry open the end and replace it with your own wiring or just splice into the existing wiring and run a lead to your fuse box to the IGN terminal. You can easily make your own metal "jumper" tab for the junction block. These can serve as IGN junctions or common 12V power lead junction as well.

[nullshine]

Well it's disappointing that switch is turning on a little late.

Where is the sending unit for your temp gauge plumbed in (intake manifold i'm guessing?)?

So to test the switch you fired it up from cold and let it idle until the fans came on?
Did the fans consistently come on at 218*?
How many times did you get the fans to turn on?

With the Echlin switch above the thermostat I'm wondering if it's getting enough exposure to the coolant to get a good measurement.
If it's a factory thermostat I think it should be a 195*, so it'll START opening at 195*. Maybe by the time the the thermostat is flowing enough coolant to heat the switch up, engine temps are already higher? If that were true it would turn on cooler the 2nd and 3rd time the fans come on, I think.
Just a guess.

Do you have an accurate thermometer? Maybe you could do a boil test on the switch to see exactly where it's turn on point is.

[85GPLEf41]

Well it's disappointing that switch is turning on a little late.

Where is the sending unit for your temp gauge plumbed in (intake manifold i'm guessing?)?

So to test the switch you fired it up from cold and let it idle until the fans came on?
Did the fans consistently come on at 218*?
How many times did you get the fans to turn on?

With the Echlin switch above the thermostat I'm wondering if it's getting enough exposure to the coolant to get a good measurement.
If it's a factory thermostat I think it should be a 195*, so it'll START opening at 195*. Maybe by the time the the thermostat is flowing enough coolant to heat the switch up, engine temps are already higher? If that were true it would turn on cooler the 2nd and 3rd time the fans come on, I think.
Just a guess.

Do you have an accurate thermometer? Maybe you could do a boil test on the switch to see exactly where it's turn on point is.

My temp guage sending unit is on the drivers side cylinder head. And i turned it on and let it idle and then would rev it up a couple times here and there for about 20-30 seconds. I got the fans to turn on 3 times before shutting it off. They turned on @ around 218 every single time. I am going to try to borrow a laser temp reader and see what the temp is exactly at the radiator. I don't have a thermometer though to test the switch.

[nullshine]

My temp guage sending unit is on the drivers side cylinder head. And i turned it on and let it idle and then would rev it up a couple times here and there for about 20-30 seconds. I got the fans to turn on 3 times before shutting it off. They turned on @ around 218 every single time.

Ok, nothing to do with the switch being in the thermostat housing then. (EDIT: In regards to coolant flow, that is, lol).


I am going to try to borrow a laser temp reader and see what the temp is exactly at the radiator. I don't have a thermometer though to test the switch.

Let us know how it goes.

[H2Ogbodies]

Okay, that solves it then-your reading on your gauge is taking into account the head coolant temp which is always going to be the highest-your fan switch is in the intake so you have a span of about 15-18 degrees (+/- 2-3 degrees @ sensor) for the temp to drop allowing the fan to kick on. If you want to use the gauge as a guide for when your fan kicks on, then find a thermostat housing with a threaded port in it to use for the fan switch and re-route your gauge sensor to your intake. For accurate readings between the two sensors, you should place them as close together as possible.

[STROKED]

Thanks for the help all, its slowly coming along. I bought a new coolant sensor for my fan switch im wondering if this works. Guy at auto zone told me its for a 82 Monte Carlo 305ci. I need the two wire that's what he recommended. Does it matter which wire goes to the sensor? Is one ground and one reference volt? I'm planning to use this with my fan controller.

[85GPLEf41]

If you want to use the gauge as a guide for when your fan kicks on, then find a thermostat housing with a threaded port in it to use for the fan switch and re-route your gauge sensor to your intake. For accurate readings between the two sensors, you should place them as close together as possible.

I already have the temp switch installed on the t-stat housing. My housing has two sensor holes on it. One for the vacuum temp switch and one forthe temp sensor for the CCC feedback computer. My CCC system isn't hooked up so i used one port for the temp switch. So i should install the temp gauge sensor on the intake as well for a more accurate reading?

[86_442_kID]

No. Get a 12V junction block from any junkyard S-10 oe other similar GM vehicle and run an IGN lead wire from your fuse block to one side of it. Now you can use it for any IGN sourced turn on lead you need. It is not a good idea to tap into the 12V lead to your coil. The coil lead should remain an isolated circuit. It comes directly from the fuse panel 12V BATT buse bar and remains hot at all times.

Hey H2OGbodies, I was looking on the gbodyparts.com and I saw that they sell dual fans with 2 hi/low relays. Could I use that set up on my cutlass?

[H2Ogbodies]

That kid at Autozone doesn't know what he is talking about-1982 Montes did not have a switch-that is a sensor. You need a 1-wire switch that allows a path to ground once the desired temp range is reached-thus completing the ground circuit @ the relay to kick the fan(s) on. I usually look in their Wells engine management book under "SWITCHES/SENSORS" and look for a single spade switch with the right temp range and then it comes down to what thread it is-ideally you want 1/2 NPT but usually you find 3/8 NPT or 16MM. O-Reilly's carries Borg/Warner electrical engine management-they are pretty extensive-try those guys. As a last resort, go to NAPA-they have their own line, Echlin.
As for the dual fan setup with relays...sigh, I know what you are thinking-man, pretty cheap and they fit great, right? Besides the fact that they do fit a standard gbody radiator nicely, that's the only good thing. The pancake style motor is low profile which means not a lot of motor windings which results in a high amp drawing fan with a crude blade pitch. Translation: it is okay imo to use on a stock motor, not a HO one. Or, if you've swapped to R134 AC, not a good fan choice either. A nice cooling system centers around proper shrouding and airflow...it's always better to have a high powered fan that is more than up to the task and then you can dial it in. If you start with a weak fan by design, you can't dial it up as easy if you need to. As always though, cost can be an issue and space even more so. I did a 377 in an S-10 truck and I tried like heck to get a Mark VIII fan to fit but ultimately I had to go with dual 11" Spal fans-then, I needed to trim the center shroud support to clear the water pump pulley on the serpentine system. Money wasn't the issue but space or lack thereof was. lol.

[STROKED]

H20gbodies - The controller im using came with a " temperature probe" (3/8" thread).

The 82 Monte Carlo sensor uses 1/2" thread (that's the only reason i was thinking of going with it on the intake), but i don't think this sensor will work because its for a gauge and be different voltage.

I'm going to run the probe that came with the controller into the water pump, by using a 3/8" to 1/2" adapter.

[STROKED]

Want to say thanks to everyone that helped get my electric fans to work.
I've set my adjustable controller to come on at 190F and turn off at 180F.

[H2Ogbodies]

Correct, that 82 Monte Carlo unit is a potentiometer mainly...the gauge reads temp based on resistance-this makes it a sensor-a switch is basically an open set of contacts which has preset close/open contacts which are designed to work in a specific temp range-thus acting as "switches" because they act as an engine block ground when closed-for this reason too you don't want to use any type of thread sealer on them. Use this feature as a ground activated trigger for a fan relay. Good to hear you have your fan issues sorted out.