Fan question

[Pacco]

Fan comes on at the turn of the ignition. I do have a on / off switch for the fan on the dash. Is it possible for the switch to have stopped working in the on position? Therefore not allowing me to manually turn the fan off with the dash switch?

[Ron61]

The switch could have a short in it and that would be the same as having it on all the time. Is this the only way your fan has to come on? If so, easy test is to take the wire that goes to the fan off and use a voltmeter to check for voltage at the output terminal of the switch. With it in the off position there should be none. If you also have a thermostat which will bring the fan on at a set temperature, make sure that isn't the problem. I had both on my car when I had it and never had any problem.

Ron

[Pacco]

Changed switch and fan still continues to run while key is on. What could be the problem? Could it be temp sensor?

[J Persons]

Most fan controllers function by grounding. Determine which wire goes to the fan temp controller and disconnect it. If the fan stops, the temp controller could be at fault. You fan circuit is probably controlled with a Bosch type relay. If the fan doesn't stop when the temp controller is disconnected, then the relay is probably at fault.

[ron427]

As J persons said, it could be a stuck relay..With the fan running, tap lightly on the relay. If it is stuck closed. it may then open. If so, replace it Ron

[Pacco]

Got around to checking the temp sensor. A lot of corrosion and other gunk. Ordered new part through Advance. Hopefully this will take care of the cooler running temp. Thanks for everyone's input!