zim

As usual, my electric fan on the current 91 XJ is on the fritz.
Now that the weather is warming up I am going to need it to be reliable.
My fan works when checked by pulling a wire from battery over to it. When plugged into it;s stock wiring plug, it does not come on no matter what the water temp. I would like to run a remote switch to it I think. But before I do I would like to test all of the factory installed weaknesses first. When engine is running, I get no power to the fan plug, I know that the power is supposed to come from the unit at the rear driver's side of the head. How do I test that piece? Also is there a fuse that controls this circuit? thanks all

DFlintstone

Not much help here as my 90 is very different than your 91. That said, if you DO have a lone relay on the left inner fender, it's probably the fan relay. It should not come until about 218*. Also it should come on when the AC compressor is running, or defrost is selected on the dash. (pretty sure there for a 91).

There is a diagram in my signature on relay function. When you find the relay, you can test allot of stuff at the relay socket. Check it's connections, also you can swap it out with another that looks the same to test. They don't fail often, but the fan draws allot of current through that relay, and sometimes way too much when they get old.