So I had the blower motor on my truck stop working the other day so I took a look at the resistor. When I turned on the fan it was glowing but not turning on the fan. I jumpered the resistor and it worked. When I removed the jumper it continued to work... so I figured ok, I'll still replace it. I did and it worked fine, but this evening it was back to its old trick. The resistor was trying to roast itself. Any ideas? The fan doesn't sound like its bad, when it works, it works perfectly fine with normal output.

 

There might be a short somewhere or the blower is drawing to much power due to seizing up bearings. Sorry not much help.