I've got the dual electric fan setup which has been wired to run all the time. Turn on ignition--fan runs. Whoever had the car before did this and I don't mind since I only drive it in the summer anyway.

The problem is the fan now only works sometimes. The coolant temp senso is out of the equation since it is not wired in.
I know the fan motor is OK. When I turn ignition "ON" and jump the A & B terminals in the ALDL the fan comes on.

What's left to checked? Is the relay maybe not working like it should?

Bob

 

How exactly did the previous owner wire the fans up? Follow the wires from the fans themselves and see where they go I would suggest as a first step. Do they even use the relay anymore?

 

So when exactly do they NOT come on?

 

He most likely DID use the relays, if he had the fans wired through the ignition sw circuit it would have fried the ign sw by now. Replace both fan relays if they are the oval style, they were notorious for being intermittent especially under heavy duty cycle like you have. Inspect the relay plug closely, look at the contacts for signs of discoloration. If it looks discolored fix that also or the new relay will overheat and prematurely fail.

 

They look to be wired thru the relays still. They will work or not work intermitantly. There is no pattern.
There are two of them correct? One on the rad support and one on the inner fender. Why two? One for each fan?

Bob

 

yes there are two relays, one for each fan. usually around the drivers side firewall or around the radiator.

 

Well the relays did not do the trick. The passenger side fan will not come on at all. The driver side will run when I ground A and B in the ALDL. Passenger side will not run at all.
Started car and the driver side ran for a few seconds then stopped.

bob