This may be a repeat if so I apologize I was not able to find any threads on this specific topic. Ok I have no heat or AC. When I turn on my heat or AC air will blow out of the defrost vents only. The air is neither cold or hot, just luke warm air. Any ideas?

 

Probably have a disconnected vacuum tube under the hood that controls the actuators in the HVAC system.

I need to know more about your truck to help out further... Year/options at the very least...

 

Sorry I have a 1996 S-10 Blazer LT. What other info would you need. Thanks

 

Auto or Manual climate control?

 

Manual Climate control