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My 85 corvette cooling fan will not shut off. What is wrong?
better than the other way around.
check the relays to see if they work, sounds like you might have one stuck open allowing power to go through all the time. There’s honestly is not my strong suit, but it means you have the circuit being closed all the time. Unless you possibly were checking codes with a paper clip and forgot to take it out!
I kind of assumed that but I do not know where the relays are located. or how many may be involved. could it be the temperature connection or maybe the fan relay.
there may also be a link to an ac switch here....if the car think ac is on it runs the ac.
OP the shop manual is really good for this kind of thing. there are flow diagrams to steer u in the right direction. that said there will be ithers here who have the same problem for sure.
Here is the main fan relay . You may have the same problem as I had, the plastic coating shrinks down allowing the wires to touch, check all your wiring for this.
Yep. The CTS codes 14 and 15 if set, command fan on at all times.
A test for "stuck relay": If fan turns off with key = OFF, the relay turned the fan off when the ign source from the key was removed. The relay isn't 'stuck".
If fan runs at all times, even with key = OFF, the relay IS stuck. The main fan relay in an 85 is located on the rear of the Left Hand wheel housing, kind of under the master cyl. Un plug it, and if fan stops, replace the relay.
If fan runs at all times key is on, but fan is off with ignition off, and there are no DTC 14, 15 suspect the air cond high pressure "fan request" switch has failed open. (Open circuit causes fan to run). Remove connector from high pressure fan request switch. It is located on the small high pressure line adjacent to the Right shock absorber. There are two switches side by side. The fan request switch has two black wires on it. Remove the connector and jumper the two terminals together. If the fan stops, the switch has failed. The key must be in RUN for this test.
I unplugged the relay and the fan stopped with ignition off. have ordered a new relay. thanks for your help.
Here is the main fan relay . You may have the same problem as I had, the plastic coating shrinks down allowing the wires to touch, check all your wiring for this.
wiring seems fine. i check further when i replace the relay. thanks
Most relays fail where they do not close. It would be unusual to have one that is stuck closed. Good luck with the new relay.
If the relay does not fix it, then you going to have to find out what is energizing the relay. This wiring diagram might be close enough (not sure) for you go get a head start. Disconnect the items I suggested and see if the fan stops.
