1967 Camaro 2005 GTO LS2: Wire fans off ECM?

[1967ls2]

I have a 1967 Camaro RS/SS with a 2005 GTO LS2 installed and it has been running great for over 2+ years. I just recently installed a new LSX style aluminum dual pass radiator with 2 electric fans on it. My last radiator/fan setup I had a switch that I would just toggle on and off as needed. This new fan setup comes with the necessary relays, wiring & a 180 NPT sensor that is supposed to control when the fans come on and off. With that said, the LS2 engine has 1 port in the driver side of the head which is used by the computer and the other one I was using for my electrical temp gauge. Now I have the 180 NPT sensor and no where to install it. I tried making a T piping out of NPT which I believe will do the trick.
I was wondering, since the computer is already using one of the ports for the temperature, is there any way to tap into the computer or wiring and have it turn on and off these fans some how?
I have been searching on the internet for a while for some answers and haven't found anything concrete. Any help, guidance or suggestions would be greatly appreciated. Thanks in advance.

[Chris 68]

yeah the factory LS2 GTO computer has 2 wires off of it that run each of the two fans. These should be conected to relays, i believe these two wires off the LS2 computer are ground switched. Depending on who modified your engine harness and computer, you should have these two wires, I don't have the pin outs or wire colors in front of me but if you can't find them PM me and I'll and send you them, I have them somewhere here on my computer.

[CarlC]

...and they can be set for different temperatures, i.e. high/low and/or A/C.

[1967ls2]

I have the pin numbers in front of me. It says that pin 36 is for the low fan and pin 56 is for the high fan. My new fan setup has 2 relays and is already wired up. From each relay there are 2 power wires that go to 12 volt keyed on and 2 wires that are both ground wires that are designed to go to the 180 NPT sensor which is supposed to be plumbed into the a coolant port. So if I take the 36 pin wire and run it to one of the ground wires from the relay and the pin 56 and run it to the other ground wire from the relay, then the PCM should trigger the fans at the computers pre-set times.
Not exactly sure but I would assume the low fan would trigger at a lower temperature and turn just one fan on and when the engine gets hotter then it will trigger the other fan so both of them will be pulling.
Is that right?

[Chris 68]

yes that is correct, I beleive they also shut off if you are moving above a certain speed. The temperatures that trigger the fan and the function that shuts off the fans above a certain MPH can be adjusted in the computer if you have a tuning program, but the stock settings should be fine. BTW if you are running an A/C system you CANNOT turn the fans on for the A/C system through the LS2 computer unless you have a body control module from the GTO. I'm currently configuring my fan set up for my LS2 and A/C system so if you need info for that let me know.

[Chris 68]

BTW post some pics of your car and engine! I'm in the process of wiring my set up right now, how do you like the LS2? I'm very curious on how these thing drive day-to-day

[1967ls2]

I've had my LS2 in my 1967 RS/SS Camaro for about 2.5 years so far. I haven't had any issues with the engine what so ever. It's my daily driver, rain or shine. The 6 speed gets great gas mileage on the freeway with my gearing. Your gonna love it!

I have posted a lot of pics of the vehicle and the build at cardomain.com. Here is the link to view my ride.

http://www.cardomain.com/ride/2911913

[Chris 68]

looks amazing man! I actually have seen your car before on there, I think I even snagged some pictures off of there as well. Yeah i'm making my 68 my daily driver as well, thats a big sigh of relief to actually know someone who uses theres day to day, how many miles have you put on it since the build? Did you leave the engine mostly stock? If so how is the performance aspect of the drive? Also what did you do for your clutch master cylinder?

[1967ls2]

I bought the engine with about 18,000 on it. I probably put around 10-15K or so. I installed shorty headers from S&P, other than that the engine is bone stock. Lots of HP & plenty of torque, great for the every day rider. You can always do a cam, heads, intake, etc. for more power down the road. Also check out S&P for the clutch master cylinder plate. They have an adapter plate you bolt on behind your brake booster. Cut a hole, weld the clutch master cylinder (I used one from a 2000 camaro) throw arm to my clutch pedal, I had to make a few fittings to get the clutch cable to fit with the T56 throw out bearing cable and then I was good to go.

[Chris 68]

I'm in the same boat, got almost all the swap parts from s&p and got my engine from a wrecked gto. I also got the camaro mastercylinder and put the camaro slave in the t56 just have to get aroun to welding that bracket in. I plan on doing a cam and maybe some head work or new head all together. So that clutch pedal set up worked out well? that was one of my biggest concern, i dont want to drive down the road and bam my pushrod broke off the pedal

[1967ls2]

Nice! I'd be interested in knowing what kind of cam you put in, how much it cost and how easy it was for installation and of course the power gains. Same thing for the heads. Those are things I was planning on doing down the road. The clutch pedal worked out just fine. I haven't had any issues with it since I installed it. My fittings have held together perfect since I installed the line. I did have to grind the head of a bolt down where the clutch pedal meets the linkage up top because it was making contact with the brake pedal I believe but that wasn't that big of a deal. I'm gonna try to run those fan ground wires to the PCM tonight if I get some time.

[Chris 68]

yeah let me know how that works out for ya. I'm talking to a few local shops right now, the latest I got this morning was 3700 (1500 in labor including dyno tune) and that’s for a new set of heads, cam and springs, gaskets, etc.