My blower motor is only operating on high speed. I know this is a typical failure mode of the resistor pack so I bought a replacement from NAPA.

I read that the resistor pack usually fails (most specifically the thermal fuse on it) because of excessive current draw from a worn blower motor. I used a clamp on ammeter and found the blower motor to be drawing 14.4A. This seems reasonable to me and no cause for concern. The resistor pack connector looked perfect.

The replacement resistor pack worked perfectly and all the speeds work again. I believe the only other thing I can do to be certain it's not going to blow again would be to inspect the speed control switch and connector above the temperature slider. I've seen some photos of crispy connectors here. Am I missing something? I've read that you *must* replace the blower motor if the resistor pack fails.

 

Is the motor squeeling like a pig? If so, the motor has the bushings shot and has too much resistence

 

Nope the blower motor sounds normal.

 

My blower motor sounded normal too, but the current draw it had melted the connector on the blower switch, and took out the thermal fuse in the resistor set.
I replaced all three parts, but I don't know how much current that the blower motor normally draws. 14 amps seems like a lot to me, but maybe not....I got the motor at Oreilly, a VDO brand...

From all the threads/posts about blower resistors & switch failures, it seems fairly obvious that those parts aren't heavy duty enough for longevity....