I own a 97 impreza obs & had taken it to a local dealer for a/c servicing several times before it worked properly. right after it was fixed and even now, I am having a strange problem. the a/c works fine while the car is moving but, if stuck in traffic or sitting parked with the a/c on, the temp gauge goes up and it blows hot air out of the vents. if u start moving the temp goes down & the air will blow cold again. I am puzzled and would appreciate any advise or suggestions in this matter. thanks

Your fans on the radiator isn't working. Could be a bad relay related to the fans. Since the fans don't come on when the A/C is on, then we can count out the temp sensor that kicks them on when the car gets hot.

 

Since your car isn't moving, air isn't moving through the evaporator and the radiator, and that is where the fans come in to move air through the system. When your car is moving, air is flowing through the system and that's why your car's temp is stable and you get cold air.

My wife's car did the same thing. We had a/c work done at the dealer and they forgot to re-connect the electric cooling fan plug/connector. It's located under the front passenger side near the radiator. One side of connector was easy to find because it was just dangling...the other was pinched on the metal plate that supports the radiator. Hope this helps.

You can also wire both fans to operate together for a little extra cooling. On my old '92 Legacy VZ I did this to help cool :cool: it down faster (It was converted to R134A). The engine thermostat will stop it cooling the engine too much.

 

Allan :-)