Nukundu

New on the site – having issues with my a/c - blows very cool air if I go slow but going fast blows warm air or I can go fast just gently touching the gas pedal goes back to cold air, the freeon was vac out some months ago to make sure I had the proper amount on. Any ideas????

Thanks in advance

Don06

I would suspect a vacuum problem but I'm not sure if these even use vacuum actuators. In older vehicles, they used vacuum actuators to control the doors that direct the air through the heater core or AC evaporator. Many GM vehicles used a vacuum operated heater valve. When the throttle opens, the engine vacuum goes down so any leak can cause it to lower enough that vacuum actuators can't overcome spring pressure. Many newer vehicles use electrically operated solenoids or stepper motors.

AJochum

I've been having problems similar to yours for the past year or so. A/C has a mind of its own. Sometimes it works, other times not. I'm becoming convinced that it's in the knobs. To get it to work I rotate the right one (floor, defrost, etc), then the cold to hot (left), push it on and off, etc, over and over again. Suddenly it will work.

ChevyMgr

Any special way you tilt your head when you have to do this?

I'm thinking a new a/c control head may be in your near future.

Without seeing and testing the a/c I've got no bullet proof fix for Nukundu

urbexHHR

I know on my car if you shift it into neutral the a/c stops blowing cold air....

hotbird89

Sounds like one of a few problems:

1. Dirty condenser or cabin air filter
2. Imroper refrigerant charge (probably low)
3. Bad low and/or high pressure switch

I have seen this way too many times, and mostly is a low charge that causes the low pressure switch to open on moderate to heavy acceleration.