C1 (60) How do you test the heater fan switch?

[Jim K.]

Can anyone tell me how to test my heater fan control switch? I turn my ingition on and turn the switch to low & high and the fan (the fan motor has been rebuilt)doesn't turn on. I'm going to check the fan motor out by connecting a wire lead to the fan motor wire and connecting the other end to the positive side of the battery. I was thinking that I should be able to check the switch with an ohm meter? Any help or advise would be helpfull. Thank you in advance.

[John O.]

Re: C1 (60) How do you test the heater fan switch?

Hi Jim

Make sure you have the fan motor grounded good.If the motor was freshly painted, you might be loosing ground.Did the switch work with the motor before you had the motor rebuilt? What I did with mine after refurbishing it was, I took the motor and touched the body to the ground terminal on the battery and touched the wire to positive side.I had to spin the cage a little to get it going cause it sat awhile. Been working good ever since. But check the ground.

Good luck....John

[John O.]

Hey Jim..........check the fuse first *NM*

[John M.]

Re: C1 (60) How do you test the heater fan switch?

John is right, the ground is the most likely candidate. On you car, the only source of ground is throught the bowden cable that controls the hot water valve.
The cable connects to the heater console plate which is grounded to the wiring harness. Then the path goes to the heater valve, which conducts the ground to the mounting plate for the valve, which then conducts to the fan housing, which then conducts to the fan assembly. You can trouble shoot the ground by hooking a wire to the negative terminal on your battery, and then start touching each of the components mentioned until the motor comes to life. When it starts to work than back up one component and that is where the ground is being lost.
Probably the 2 most likely candidates are paint under the screws mounting the fan assy to the fan housing, and the foam gasket being put on the wrong side of the heater valve mounting plate, insulating it from the fan housing. If that is the problem, you do not have to pull it apart to move the foam gasket, just pull the motor and run a tek screw throught from inside the fan housing to electrically bond the housing to the valve mounting plate.

Regards, John McGraw