I have an 88 GTA trans-Am (350ci) and just recently the primary (driver's side) fan has stopped coming on at all....all the relays, wiring and the fuses are okay and when the aldl is in diagnostic mode there are no fault codes displayed and the fan will run so I figure that whatever the aldl bypasses to make the fan run is the problem. I'm guessing that the problem is the temperature coolant sensor located under the thermostat housing on the front of the engine...there is 4.8v present when the lead is disconnected. I have tried to measure the resistance of the sensor but the two little pins are a PIA to get at so I would appreciate it if anyone can suggest any other causes that I may be missing before I go to much more trouble.....and Yeah, I did post this before and I got a couple of answers but hey guys, I live in England...I can't buy adjustable relays & I can't burn my own prom or anything so i just have to go with stock parts!!
THANKS GUYS...(and sorry if you read this somewhere else but I need all the help I can get before my car cooks itself!!!)

 

The coolant temperature sensor would be my guess, unless the motor is not actually reaching the approx 226 degrees F that is required to turn the fan on when the A/C is off. Does the primary fan turn on when the A/C is turned on?

Tim

 

Good question...I don't know.I'll test it out tomorrow....2" snow last night so not much got done today!!Thanks for the reply.

 

hey, i have the same exact problem on the same exact car.....freaky huh????
anyway, its not a big problem now, being winter and all, but its gonna be bad in the summer. what happens when i turn the ac on is the fan goes for about 5-10 seconds, then switches off, and no one can figure out what is wrong with it.....

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1988 GTA
TES headers
Flowmaster exaust
TB airfoil
165 Tstat
K+N's
JET chip
kenwood head unit, xplod amp, poineer 3 ways
weird rattling noises
dying 350
crappy paint
700R4 on its last leg
hood that won't open