I used tunercat to program the VATS, EGR, and all the other crap out of the computer to stop it from throwing codes.. pretty much drove the car during the summer.. but now its out early and i've noticed i have little heat.. found that the #1 fan likes to run.. alot.. I programed it to only come on at 93deg Celcius with tunercat.. but no change.. the fan is set to come one when the AC pressure reaches a certain PSI... since none of this is wired.. as i haven't got the AC to work yet... would this be why my fan is over coolign the car? Has anyone else run into this?

 

If you're overcooling that badly, I would suspect the thermostat rather than the fan. It is odd that it's still coming on though. Is it on all the time, or just coming on too soon? If it's on all the time, I'd check the relay and wiring to it; if it's coming on too soon, I'd check the temperature sensor on the front of the motor and its wiring to the PCM. The correct resistance values measured across the sensor are:

Temp, deg. F Resistance, ohms
-40 100700
0 25000
20 13500
40 7500
70 3400
100 1800
160 450
210 185

 

going to do a bit more investigation.. but i know the fan is off when u first start the car.

will measure the sensor.. but 99.9% sensor is ok since its new, less then 5000miles on it.

 

One other thing that just occurred to me: depending on how the input circuit for the AC refrigerant pressure sensor is wired, it could force the fan on when no sensor is connected. You should be able to find out if that's the case by taking a piece of wire (or a paper clip) and sticking it into the refrigerant pressure sensor connector so as to connect pin C (sensor signal, red wire with black stripe) to pin A (sensor ground, black wire). If this has no effect, try connecting pin C to pin B (5 volt reference, gray wire). If one of these does the trick, then you could leave the paper clip in, temporarily splice the two wires you jumpered together, or get a refrigerant pressure sensor, connect it, and zip-tie it out of the way in the engine compartment (with something covering the opening in the end so that dirt doesn't enter the A/C system when you connect the rest of it).

 

My a/c pressure sensor plug is just laying in the bay with nothing hooked up and no fan problems here.