I have a 97 Trans Am fans do not come on, Temp about 140 , checked fuse next to relays, switched relays around, turn a/c on, jumped DLC 5&6 engine off key on , reset pcm, after trying all those fans did not come on. If i jump a wire between d1 and d4 (on the primary fan relay) a fan came on. I did a search and did not see any with similar problem. Any suggestions on what to do next?

 

I thinking it is a relay or a wire not plugged it all the way at the relay. I hope this info helps... http://shbox.com/1/4th_gen_tech2.html#cooling

 

I rechecked the relays in the fog lamp and all are ok, looked at all the wire plugs and all are clean and plugged in.

 

My 94 had the same problem. I would allways haveto drive with the defroster on or my car would overheat. I guess that kicks the secondary fan on. I put in new relays and CTS and nothing.

 

I also unplugged the c100 connector and grounded the drk green and drk blue with the key on and the fans did come on

the fans do not come on with the a/c

the fans do not come on jumping 5&6 on dlc with key on

 

That was a good step. At least you know the relay control circuits are good from C100 to the fans. What is left is the wiring from C100 back to the PCM and the PCM itself. It would be nice to monitor with a scanner to see if the PCM is actually commanding the fans on or not. If it is commanding the fans on and you don't see a ground from the pins of the PCM, then I would guess a driver in the PCM is bad.

 

i had the same problem , never did figure it out so i just bought a slp manual fan switch and now they work, except i sometimes forget to turn them off and they kill my batery

 

I have not had a chance to get ahold of a scanner but I was checking continuity on drk blu 473 to the relays and from the c100 connector to j2 is ok but from the c100 to f5 I dont have good continuity about .750 and from j2 to f5 I dont show anything. Does anyone know where the splice is located? I think that I should have continuity at all those points am I wrong?

 

What a pain in the A**, bro. I hope you get this tracked down. good luck and let us know the out come.

 

I had a problem like that, I hooked up a manual fan switch with a writeup someone did where I hooked into the lines near the pcm, blue and green I think, so I have off, high, low and it shuts off with the car, so I just leave them on low all the time, or high at the track, works perfect.

 

You're right. The splice might be under the fuse panel.