My ac only for works on defrost in my 01 1500., It's not wild vents but wish that was the problem because that was an easy fix a couple years ago. I have vacuum on the switch but don't know where to go next. I've done a lot of searching but can't find anything else other than it's an expensive problem and you have to remove the dash. Is there a write up or a way to know if the switch is operating or better yet a write up?

Thanks in advance for any help.

 

Do any of your other vents work? If not, I would suspect a vacuum leak somewhere..... maybe even at the selector valve itself.

 

No other vents work.Any way to test the switch? If I pull the tube harness off the back of it I can feel the suction and hear it as well. I know it goes behind the dash when it leaves the switch but where? I assume I have to remove the dash but hoping there's another way to check.

 

Have a look in the service manual.... might be some diags in there that would help.