Electrical: My Heater Fan Switch Is Trying To Kill Me

[Joe Tondu]

I've found that I am reasonably competent working on my '50 Champion. But when it comes to electrical, I practice diligent avoidance. Witnessing, on several occasions, cars engulfed in flames, has damped my enthusiasm to fiddle with wiring. Is Rome burning?

Imagine my horror to discover that my heater fan switch was as hot as to light a cigarette. No exaggeration, I have the second degree burn to prove it.

How long this has been going on is anyone's guess.

The slow setting (fully pulled out) has never worked, and upon testing and inspection, seems to go hot when in this position.

Are these switches repairable? A new replacement would be preferable but I don't see them in the SI catalog.

[graylark]

A lot of the old 6 volt car heaters had a resistor built integral to the switch to drop the voltage resulting in a lower speed. These were relatively high wattage resistors and it is normal for them to be too hot to touch.
The fact that it is getting hot means it is working as resistor. Your fan motor might need to be lubricated causing there to be drag on the motor. If you could find out the value the resistance should be you can check it with an ohmmeter to see if it is out of tolerance. Usually they would just burn out to an open circuit, but as noted that it is getting hot indicates that yours is not burned out.

[TWChamp]

I'd also clean all the connections on the switch, as any resistance will cause heat.
I also have to check out the wiring in my 1950 Champion because my blower fan hasn't worked since I bought it.

[mbstude]

Part number 526352. You can buy an NOS one from us at http://mystudebaker.com/