I have plowed through the threads on this site on the AC heater blower motor but have not come up with an answer. I am restoring a 71 Comet GT. The AC heater blower motor is new, but only seems to work at low speed. My battery is fully charged, so that is not it. I connected the orange power wire on the blower motor to a direct 12 volt current and it blows at high speed like it is supposed to do. The motor is good. I took the fuse out of the fuse block and wire brushed the contacts, so I know there is no corrosion like I hear some of you talk about. Now what? I assume the only thing it can now be is the rheostat? What else might it be? I do not think it would be my heater/ AC/ fan switch control on the dash? Thanks for any suggestions!
Are all the wire coils on the blower motor resistor in tact? All its contacts clean? That's were I'd look first.
I would guess the blower motor resistor is bad. On the side of the blower motor assembly, unplug the wires on the resistor (small red board) remove the resistor and give it a visual inspection.
Thanks guys. After all the hard work, I cleaned the contacts on the plugs for the blower motor resistor and the fan went to work!
Don't ya love it when the fix is simple!!! I like to use a tiny bit of conducting grease on old contacts.
agreed! I had a spring on my resistor that had fried and wouldn't make a connection. had same issue. it eventually stopped working entirely
