My blower motor stopped working on the first three settings and now only works on high. I have no idea where to start to diagnose this problem any help would be appreciated.

 

There is a ceramic device (rectifier? I can't remember the name) that is located just to the left of the blower motor, in the airstream of the of the blower. It "uses" the electricity in the first 3 settings, and the switch makes 12 volt direct to the motor on the 4th setting. There are wires going to it. It has burned out, just replace it and you are back in business.

You can just go to a parts store and have them open the books with a diagram. You'll see it.

 

Thanks for the help can I get the part at autozone or do i have to make a trip to the dealer?