So i jus got my xj right before winter and it runs great with 175k on it. My only issue is the electrical fan does not kick on. The original one was completely seized up, so i got one from the junk yard uo the road. I tested to the vatter and works fine. The engine revs high cor like 1.5 secs then goes back low, and repeats. Im assuming when the engine revs high is when the electric fan is supposed to kick on. Does anyone have any ideas? Also my first xj, and i love this thing!!!

 

Electric (aux) fan comes on when AC is selected or when engine (coolant) temp reaches a certain threshold. Not related to engine revs.

 

You might check the cooling fan relay under hood. Big square top left of relay/fuse box.

 

Coolant temperature sensor. Mine has been bad for years. Instead of replacing I just turn the a/c on if temp gets over 210. Turning the a/c on forces the electric fan to come on regardless of temperature.