Questions and Answers

Pontiac Grand Prix A/C Problem Q. Hello, my name is Russell and I am in Houston Texas. I have an 1989 Pontiac Grand Prix and the A/C has a problem it is blowing very cold, however the problem is it will only come out of the defrost vents. Any ideas where the problem is so I know where to start? Thanks for your help. Russell

A. You have a vacuum leak in the HVAC supply line. There is a vacuum storage canister under the hood that looks like a black plastic ball. There should be a hose on it that has vacuum when the engine is running. Trace this hose and you will find something wrong. There may be a check valve in line that may be cracked or broken.