Expert Advice Needed/overheating Issues


New Member
Sep 4, 2013
My 2002 Gt has an issue with overheating. I charged the a/c and this is when it all started. I was running the a/c and then the car overheated. My Mishimoto fan for the radiator is wired to the low side so I thought this might be the issue (didn't know what to do other than not use a/c). Next I had a complete exhaust installed in the car and no issues on the 1/2 hour drive home on the way back from the shop. I drove it all day the next day with no issues until I was at idle in the driveway, the RPMs went down real quick and the temp started going out the roof, no fan going??? So I let it cool down and then started up again the fan came on so I disregarded it. I next got an SCT tuner and put a tune to it, now the fan comes on for a few seconds and shuts off and its eventually overheating again cause of this. I just have no clue what to do. I got to get this fixed quick before I do serious damage I have overheated like 3 times already. I know this is the best and most knowlegeable group there is. SOMEONE PLEASE HELP!!!!!
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I had a similar problem a month or two ago. The motor in my cooling fan was worn and required extra voltage to make it work in a regular mode. If you turn the a/c on it requires the cooling fan to operate at a higher speed. With the motor on its way out and the a/c on, it required too much voltage and kept blowing the fuse. I replaced my fan and the cooling fan fuse, everything works fine now.

Note that without the a/c on the fan worked just enough to maintain the engine temp. As soon as the a/c was on it blew the fuse and immediately sent the engine temp rising.
This is not a stock fan and it doesnt have but maybe few thousand miles on it. I am thinking the problem lies where the fan gets its signal. I also wonder if there is a way to make this mishimoto fan work at a higher speed when the ac is on
all of the controls for the low and high speed fan are controlled by the PCM, also the high speed fan should automatically be turned on whenever the A/C clutch is engaged. all of the control sircuits are run through the Constant Coontrol RelayModule (CCRM). if you can i would start by checking to see when the fan is operating (high or low speed only or not at all) and from there go and check the circuits between the fan and the CCRM for opens and shorts using a voltmeter and if that doesnt work test the circuits between the PCM and the CCRM, this is of course assuming that it is a circuit issue between the fan and the module and not something mechanical or an input issue from the A/C. if that doesnt work youre going to likely be looking at either a new fan or a CCRM... not the most fun.