My gals 1991 RS 305 5 speed has a problem. The fan will ONLY run with the a/c switch on ON. I'm going to replace the cooling fan switch on the passenger side of the motor, on the head on my next day off. In the mean time I thought it be ok to drive it like it is. Now she tells me, after the motor warms up and she drives it for a while, the fan shuts off. She then has to stop and "tap" from the bottom the relay in the picture, then it clicks and the fan comes ON and stays ON until she gets to where she's going..

Does anyone have an idea of whats going on with this..? The relay is brand new.

Stone

 

That's the fan relay alright. If you have to tap it to get it to work I'd say you need to check out the connector and wiring involved. Something is loose and needs a more solid connection

 

Or else you bought a brand new BAD relay (which is not unheard of). But I's suspect the wiring and/or connector to the relay is bad. Before I bothered with a fan switch I'd get that relay fixed first - might not need the fan switch at all.

And, before I wasted a second of my time screwing with a factory fan switch, I'd get a seperate fan controller and skip the factory nightmare - I wouldn't give you a nickel for a case of factory fan switches, whether AZ junk or $100 Thermaster switches - I've tried them all, and none worked for me for more than 30 days.

 

I disagree. All the fan swtich does is close at a set temp to complete the ground. Any problems I've had with factory cooling systems ended up being bad grounds.

Do yourself a favor and pick up a factory service manual. Not Haynes or Chilton garbage. Get a GM manual. Inside you will find troubleshooting and diagnostic charts that will save you hours of guessing and frustration.

 

Ok, thanks guys.. you are the greatest help...

Stone