A few weeks ago my hvac blower started just working on high, so I ordered a Blower motor resistor and by the time I got time to put in the resistor it wouldn't even work on high. I checked the fuses but i cant figure out which fuse it actually is and I don't have a manual. I assumed it was a 30 amp fuse so I checked all those and they were good.

Its not the motor, I jumped it out to the battery and it spun right up.

It's not the resistor (Just changed it)

It may or may not be the fuse

Whats next? The dash switch?

 

Check voltage coming to resistor and fan.

 

I fixed mine last week, I had power at the motor but the fan didnt work so i replaced the motor and it still didnt work. After that i replaced the switch in the dash and now it works. Also i would shake the wires on the heater control and see if it comes on i have mine wedged in to where they work but something is loose in there too but it works for now so im not fixing it.

 

BINGO ...

Look for it to be burned and melted quite a bit.

I went through several Junk Yard looking for serviceable switches so I could cut the connector off the wiring harness to replace the bad one in my XJ and also to get a couple of spares to keep on hand.

 

Cool thanks guys! I'll check out the switch tomorrow. Is there anywhere to get the switch not from a junkyard?

 

I got mine from autozone, not my first choice but they had it in stock for about $30. My old switch was burnt inside also.

 

I've gotten into the habit of replacing the blower motor when the resistor dies. I believe that most resistors die because the blower starts pulling too much current through them. Burned connectors/wiring, as mentioned above, is another indication of excessive current draw.

 

Thats not a bad idea. It's clear that if the switch is melting something else is wrong. And the motor seems easy enough to replace.