Got my DC controller working 100%!!!

[CAMAROBOY69]

What a killer little system Jabin has. For those that dont know, this DC controller is way better than the standard relay set up to run the fan. It starts out just barely spinning as the temp increases. Then the speed progresses as the temp increases. Awesome little system. I truly put it to the test tonight. 30 minutes idling in driveway. 2,000rpm-6,000rpm and the more I abused my engine the faster the fan started spinning. I have on idea how it works but I like it a lot better than my power surgin relay.
Between the Hydratech Hydraboost and the DC controller this has been an incredible inprovement on my car in the last couple days.

[CarlC]

Good to hear it's working well for you.

Here's a tip. Keep increasing the controller temperature setting until you get the engine temperature just over the thermostat opening temperature. Then, back down one temperature scale. This will allow for the least amount of fan-on time.

Mine is currently set to go on at 180*. At this setting the engine temp is about 185*, 5* above the thermostat opening temperature. When the controller temperature setting was lower the engine temperature never budged 180*, resulting in an over-cooling condition. With this setting, if the fan comes on at a stoplight it will soon stop since the airflow from moving will take over.

[CAMAROBOY69]

I have 2 jumpers on right now and would like it to be even cooler but I guess I can keep experimenting. I was pretty sure I have it on the coolest seetting. Yeah it works well but I would like it just a little cooler.
My thermostat is 160*

[CAMAROBOY69]

I have the 8,10 and the 7,9 jumpers on right now and according to my temp gauge in my car it never gets above 205.
I dont know how to get it to run any cooler than the way I have the jumpers set up. If I throw the third jumper on somewhere will that make it run cooler? I am not too concerned. THe only way it would ever get to 205 is if I was just holding the gas to the floor for 30 minutes. The 205 was the hottest it got and that was a very long time sitting in the driveway. In real life I would be moving every few minutes even if I was stuck in traffic. If you think the 3rd jumper will cool it even more let me know. And let me know where to hook it.
Mabey I could even relocate the probe? Its currently in the lower passenger side of the radiator.

[CarlC]

If your engine temperature is 205 then the fan should be at full speed using your jumper configuration. I don't believe that there will be a 55+* temperarure drop across the radiator.

You may want to verify the temperature gauge calibration. Is it electric or mechanical? There are various ways to confirm the calibration. 1) An infrared temperature sensing gun on the upper heater hose 2) Temperature crayon on the thermostat housing 3) Candy thermometer inserted in the radiator throught the radiator cap opening.

Another quickie way is start the car cold and monitor the heat in the upper radiator hose with your hand. You should be able to feel when the thermostat opens since the hose will get hot. This is the thermostat opening temperature (160* in your case). Check the gauge and see if it reads 160*.

[CAMAROBOY69]

The temp gauge is an electric Autometer gauge in the driver side of the block. I am almost certain it works correctly because if I just wire the Mark VIII fan on all the time then the temp stays perfectly at 160*. If I drive down the road it is 160*

[Larry Callahan]

I have a similar system made by a company that is no longer around. It LOVE that controller. Does this new one cause the fan to whine? Mine does. It may get annoying some day but for now I think it's cool. Kind of like a high power dc motor you hear on some cnc equipment. The pitch of the whine also changes as the rpm does going away when at full rpm. I'm sure it's a result of the square wave pulse.

Also, does anyone know if it draws power when the fan is off? I'm pretty sure my unit draws a tiny bit of power all the time even when it's not running.

[CAMAROBOY69]

Yes Larry I noticed that last night. WHen the fan is moving there is a high pitch whine. My car is so loud I dont even only notice the sound. However when the engine isnt running I heard it whining like a tire loosing air. When the key is in the acc or on position.
I have mine wired with the ignition so I hope that there is nothing drawing power with it turned off. I wired it so when the key is off, everything in the car should be off too.

[CarlC]

Yes Larrry, same pitch but hardly noticeable. With the hood closed and the engine running it cannot be heard, and you've heard how loud my car is. It also carries through to the stereo even with the filter, though I don't notice it when "Girls Got Rhythm" by AC/DC is cranked.

Adam, at what gauge temperature does the fan start to come on?

[gmachinz]

Your gauge is reading engine outlet temperature which is different from engine inlet temps. You need to verify temps going back into the pump to measure actual temperatre drop accross the radiator-that gives you an idea of heat dissipation performance. The controller does not respond to outlet temps. If your motor is building 55 degrees of heat then I would look into a higher flow pump to remove the coolant faster-that will allow the controller to read a higher temperature longer and it will adjust fan speed accordingly. It is possible to see a 55 degree drop across the radiator if your fan is powerful enough. The controller will see to that. -Jabin

[CAMAROBOY69]

Jabin,
Do I have my controller set up to run as cold as possible right now?? Or can I add the last jumper and cool it down a little more?
CarlC,
I am not sure what temp the fan starts to turn at. I will have to verify that over the weekend. Tomorrow will be a huge day for me. I have a massive list of stuff to get done. I drove it again today in 40degree temperatures. When I came to a stop the engine temp stayed around 180-185 in stop and go traffic. I can live with that but I would like to see it stay even cooler since its only 40 outside. In the summer I know it will run closer to 205* in traffic. Still not terrible but I would like it cooler.

[baskin]

www.dccontrol,com/troubleshooting.htm


Larry, do you have one of the old psm units?

[Larry Callahan]

Yep, it is a PSM unit.

[Larry Callahan]

Ah ha, it does pull current but less. I think this may be what I need.

The VK-35 is a retrofit for the PSM Variflow. The replacement kit includes everything needed to easily replace the controller using your existing sensor and wiring. Added benefits include significantly lower off-state current draw, increased output current, added safety features such as multi-step over temperature control, and improved reliability.

[baskin]

The PSM was a decent unit, it was just under powered. I originally designed it to run two 7A fans on my Shelby so 25A was about the design limit for current. What’s surprising is that there are still quite a few of them still surviving running Mark VIII fans, which are way past the limit of the controller.

The DCC doesn’t draw any where near the current when it’s off and actually has a better sound to it in that I tuned the oscillator so that it doesn’t have the low frequency pitch when it ramps down. Overall, it's a much better design.

[CAMAROBOY69]

My car was being worked on most of the weekend and tuned. With the DC controller hooked up the engine was at 210* I really need to get the engine running cooler. HOW DO I DO THAT WITHT THE DC CONTROLLER???? Do I put another jumper on or what. I have only a few more days to get this issue resolved.

[Larry Callahan]

The PSM was a decent unit, it was just under powered. I originally designed it to run two 7A fans on my Shelby so 25A was about the design limit for current. What’s surprising is that there are still quite a few of them still surviving running Mark VIII fans, which are way past the limit of the controller.

The DCC doesn’t draw any where near the current when it’s off and actually has a better sound to it in that I tuned the oscillator so that it doesn’t have the low frequency pitch when it ramps down. Overall, it's a much better design.

When installing the PSM unit I was told it had to be within so many inches of the batteries. With my batteries being in the trunk I didn't like having to running power from the PSM unit in the trunk to the fans in the front. Is this the case with your unit? I'd sure like to put it under the dash or some place up close. I'm sure that length of wire causes some loss. I did run wire much larger then needed but still. That's a long way to go for the temp sensor and the power.

[CAMAROBOY69]

I think I am going to try and move my sensor to the bottom of the radiator. If that doesnt work I might end up running a bypass emergency switch so the fan will run all the time. I only have 4 days until the event and if I dont gen an answer then I will bypass the DC controller. Hate to do it but I dont want to run 210 at the track if not necessary. Hopefully the probe relocation will help.

[Dust87ss]

I think I am going to try and move my sensor to the bottom of the radiator.

Try to get it as close to the radiator outlet as possible; this should give the controller the most accurate temp reading.

[baskin]

Sorry about the giant fonts on the last post, I used word to check the spelling and evidently had the font size set to about a billion

The lower resistance cable helps some, but it's actually the inductance that causes most of the problems htp://www.dccontrol.com/faq.htm#batt but there's a filter available so that you can run the power from the back. http://www.dccontrol.com/componentsR1.htm