Have a problem with my fans failing to turn on. I can get them to come on when I install the jumper wire on the test port in the interior. This tells me that the fuses and relays are good. However they fail to come on with the A/C is on or when the car is running warm. Any ideas?


94 Z28
auto

 

Does your a/c actually work? The fans won't come on if it does not. Also, what temp are you calling "warm"? Fans don't come on until 226°. Have you checked with a scanner to see if the fan on command is actually indicated during the times you think it should be?

 

I let it get about 3/4 up on the factory gauge. Did not want to let it go any furhter than that. When I drive it is fine, but if I have to sit still it heats up. The A/C is not charged most likely. Maybe I will have the parts store hit it the scanner. It seems like the switch is bad, but the pump is fairly new. Any way to jump just the swicch to test it?

 

There is no switch. The PCM controls the fans based on temperature (and other inputs). A scanner will tell you the temp the PCM sees and whether the fans are commanded on. We know your fan control circuitry from the PCM to the fans is ok, since they come on when you jump the DLC.

 

I had the same problem, until i checked the grounds and realized that i had painted the contact on the front of the car where the fans are grounded to, after i sanded them a bit, the fans kicked right on and worked after that like they should, try that.

 

The fans run when he jumps the DLC, so he knows they can work.