Engine fan never cycles on and off.

I'm assuming your talking about the electric aux. fan (on the left), as the bigger fan on the right is a clutched fan, driven by the motor.

Towards that end...there is a relay, usually located on the right side of the engine bay (over the fender). (At least that's where it's at on my 89 Renix XJ)

Another possibility to look at would be AC or defroster. If either of those two vent options are in use, the electric aux fan will be engaged (because the AC compresser is activated)

Forget I ever asked. I'm a moron.

's alright. Moron attacks come to all of us at times :twak: