I have a 1964 Buick Electra with factory a/c. My heater fan won't shut off when i turn the key off. More precisely it won't shut off if the A/C is on. If I set it to vent or heater it will shut off with the heater fan lever and I can adjust the fan speed. If I turn the fan lever to on in any setting it stays running even when the key is turned off. Any thoughts or ideas are welcome.
So just so I understand, with the AC on, it wont shut off, but with the heater on, it shuts off? Maybe the power going to the compressor is back feeding to the heater? Its kind of a guess but I would start looking at the heater controls/ switches
Is this "out of the blue" or did some work get done to the car recently? Does the switch feel the same when you move it around?
This is a complete frame off resto. The firewall and all the A/C components including harness is from a donor car. My car did not originally have A/C.
Probably the high blower relay. I just did one on a '68 & got the relay from advanced. Bring the old one with you to match to be certain. Tom T.