So, I've had to replace my blower motor 3 times, the first it went bad and the resistor did too, and then after burning up 3 more resistors, I replaced the motor I had put in with an OEM one, same with the resistor and harness plug. Now its starting to do it again, after only a few months. I'm really quite disgusted at this point and I really have no idea what else to do. I just replaced the engine in this truck, and if this is how its going to be, I'm starting to regret doing so...

 

Any solution yet? I too have replaced them all multiple times and they continue to burn out at the harness.

 

Look at the wiring diagram, to see how the circuit works. I suspect the switch provides ground path for the motor. Find the ground, inspect, and clean it, make sure it is getting a GOOD ground.