A.c. Problem

[dbamsch]

I have a 1999 Yukon. The fan speed switch only works on high speed and while mode is for max air. All fan speeds do not work for any other modes, (normal cool, heat, etc.) We do know the blower resister is ok. Do I need a new switch assembly, or will a computer reset fix this?

 

Thanks

 

Dbamsch

[bill190]

To find the specific cause of the problem, you would need to test the various electrical components using a wiring diagram and a multimeter. You can get factory wiring diagram along with a factory service manual set from your GM dealer (There are 4 books in the set for my truck).

 

The alternative is to "guess" and start replacing parts at random.