Air only blows out of the defroster
2002 GMC Yukon Denali XL heat or AC
only blows out of the defroster I have
replaced the Actuator and the heater
control unit don't know what else it could
A lot of the vehicles that have the climate control modules will default to the defroster position when there is a problem, check if yours has a module that controls the actuators (versus direct operation by dash switches). The module may be bad.
The control unit is the module I have replaced it with no change
I uploaded some PDFs that may help, copy and paste the 3 links: https://drive.google.com/open?id=0B7qtH3Vy2sdBZnNkcEpwa1pFUlk - https://drive.google.com/open?id=0B7qtH3Vy2sdBYjV5S3NzWmZqS0U - https://drive.google.com/open?id=0B7qtH3Vy2sdBcHZkODFDSXpNaW8 - when you had actuator out, did you check mode door or cam assembly for freedom of movement? i know it too late now, but whenever I install a new actuator, I try to plug it into the wire harness and test that it is functioning, if not then I know it's an electrical or module issue.
Looking for a Used Yukon XL in your area?
CarGurus has 609 nationwide Yukon XL listings starting at $5,995.
Search GMC Yukon XL Questions
GMC Yukon XL Experts