1986 Trans Am 305 LG4, single fan.

Fan isn't coming on, but does work with AC on. So did this testing...

Fan relay has these wires... Red, (2) Brown w/stripe, Green, Black

Jumped the Red and Black ----- Fan works
Grounded the Green wire (ignition on) ----- Fan works
Grounded the blue wire at the fan temp switch (ignition on) Fan does not work

So, it seems the fan relay is working and the fan motor is good. My problem seems to be somewhere between the fan temp switch in the head and the relay. Where does the blue temp switch wire meet up to the fan relay? What else should I check?

If I can't find the problem, I may just hook up the Hayden relay to the green wire, but would prefer the stock system to work.

 

Maby it is just the switch in the RHS (passenger side) head.
Un-plug the wire that goes to that switch and ground it with ignition on and see what happens.

 

That's the blue wire I mentioned that I grounded with the ignition on. I should of said I unplugged the fan temp switch wire and grounded with ignition on. It didn't work, which is what really has me confused.

 

oh ok, have you traced that wire see if it has broken anywhere.
i think that wire goes to the ECM, there is a way to check the computer with a paperclip (i think) it shorts the system and turns the fan on that way you know if the it is either the "switch to ECM" or "ECM to fan" that is stuffed.

 

No, I'll have to try and trace it tomorrow. Also have to find out where to do that paper clip test. Thanks.

 

i took this from a different post


I duno if it actualy works coz my car done use the computer anymore.