My fans do not run at all, when i first bought the car, there was no thermostat in the car, probably because the fans don't run, and now that I installed one to avoid any damage to my engine, my fans never kick on, not even when I turn the A/C on. I was told by one person that if the A/C is totally empty, the computer will never turn the fans on. I unplugged the wire from the waterpump and my fans kicked on and it kept my car cool, but the only problem with that was that once I shut my car off and turned it back it it started like crap(because the computer reads -40 degrees I believe I read somewhere). So i replaced the coolant temp sensor in the waterpump and still no fans. So I am thinking it has to do something with the computer. Is there a bypass that I could buy or someway I could get the fans to run once the car gets hot? Also, once my car gets about 3/4 of the way up, coolant begins to leak from(i believe the hose under the battery into the overflow tank) is there any easy way to fix that?

 

I have read a few forums about not having the A/C charged and it being the problem. But could it all be associated with the PCM? I have changed the waterpump,coolant temp sensor, it has a newer radiator, but when the radiator was changed out the a/c was emptied, If i end up driving it in the winter(up here in illinois) will my defrost setting not work since my a/c is not charged? Would it just be better for me to charge my a/c to see if it fixes the problem or should I go straight to changing out the PCM? Where are some good places to buy a PCM if I should end up going that route?

 

If the refrigerant is too low the AC won't function and won't trigger the fans on. However, the fans should still come on when the coolant temp is above 225 degrees. Being that you could force the fans on, indicates that all circuitry from the PCM to the fan motors is good. Short the two leads going to the PCM from the ECT. This simulates a hot engine and the fans should go on.