Greetings,

The pusher fan is control by a pressure switch in the high pressure refrigerant line of the AC system. As far as I recall, it's circuit is only powered when the AC is on.

Switch is in passenger side engine compartment down near/beside/under lower radiator hose.

You can jumper the switch wires together and if the fan runs, either the switch is bad or the pressure never got high enough to engage the switch.

Daughters' '91 240's pusher fan RARELY comes on, and believe me, she works the AC hard.

Hope this helps,rcs

Does your AC Work? The reason I ask is that the pusher fan as it is known is tied into the AC not Water Temperature. The fan is to improve AC performance at idle and low speeds (and it does really help).

If your AC system does work the temp sensor is most likely bad or got knocked off. You can bypass that switch with a jumper. That way anytime the compressor kicks on the fan runs. Added the same fan to my 86 model and run it that way. Have seen a very minor slow down the warm up time on the radiator on cold mornings where you need the AC to defrost the windshield (Disclaimer Cold is less than 45F down here). Was going to add an air temp thermostat to prevent that, but after running it over a year not worth it.
Good Luck,

Paul