The other day I finally turned on my ac for the first time. After it was on maybe 30 seconds I smelled something burning and I shut it off (it smelled like wires not the belt). Then when I turned it back on I only have the lowest setting and the second to highest setting. If I put it on low the fan runs up one notch there is no difference up one more the fan speeds up a little. When up put it on high it goes back to the low speed. I checked the voltage at the fan motor and no matter where the switch was there was 12.4 volts at the motor. I also pulled out the blower motor resistor and it looked good I did not see a burned spots. So now I am thinking maybe the fan switch went bad but I do not like to throw parts at the problem so I know one of you guys can help me out. Thanks in advance, Bill

 

This may help. Scroll down to where I go through the wiring of the blower. https://www.dieseltruckresource.com/...d.php?t=135831

Hope it helps.

 

I got it fixed it was a bad fan speed switch thanks for the help BC.