2nd Gen Non-Engine/Transmission A/C controls not working

[Coonrod]

This is not on my truck, it is on my Dad's.

It is a 99 1 ton dually 2wd 5 speed.



It is stuck in the defrost position. You can turn the control to to every position and noting changes. It will go from hot to cold.



Anyone heard of this happening?



Thanks

 

[crabman]

Coonrod,

The defrost is the default position. Check the vac. hoses that operate the door. It seems like one of the hoses is leaking or came loose.

Try doing a search on the default position of heater.

crabman

 

[GAmes]

On my 97 the actuator failed that is above the throttle pedal. If that is the case be VERY careful when removing it from the plastic arm it is attached to. That arm is attached to the hinge that holds the door inside the housing in place. To replace it you have to drop the dash to get inside the heater housing.

 

[DEngelhardt]

I had this happen. The small vacuum line came in contact with my E-Brake and melted it. Check out the line near any hotspots on your engine. Course I paid $50 at the dealer so hope this helps you.



dave

 

[RustyJC]

Loss of vacuum due to a failed vacuum line, switch or actuator diaphragm = defrost (default) position. I think there was also a problem with acid spilling onto a vacuum line that runs under the driver's side battery, IIRC.



Rusty