I have a 89 camaro RS and Im having an overheating problem where I need to keep the A/C on otherwise if I turn the A/C off it will overheat badly. Already had a problem where my radiator blew up n spilled coolant all over the street for being hot. Also I believe that my electrical fans can be a cause of that simply because they tend to turn on and sometimes they dont so it can be a loose connection I believe but need help if possible. If anybody has had the same problem and knows what can be wrong leave me a msg

Tony

 

I am not 100% on this because my 86 is different but the AC turns on the relay and when the AC is off the temp switch turns it on. Check out your fan temp switch on the passenger side cylinder head. An easy way to check it out is to ground the fan switch wire and see if the fan turns on.

 

There are different options for cooling fan system design depending on which motor you have. The TBI 5.0 has one fan controlled by the temp switch mentioned above, or by the AC switch. If the fan works with AC on, you need to replace the temp switch.

 

To expound: Check the fan switch on the passenger head-pull the lead off the switch and with the ignition in 'run' short the lead to a ground (engine will be fine). If the fan turns on the switch may be bad.

Your car isn't oveheating when the AC is on because the AC turns on the radiator fan. The AC (pressure switch or switch at control head) grounds the same signal lead that the temp switch grounds at the relay so you know the relay and fan power circuit are good.