Hello Audi lovers:
Haven't had any problems lately with my 89 100, but I have noticed lately that when the engine is under load ( near zero vacuum ) that the a/c switches from the upper vents to the lower vents, and blows hot air. It seems to be switching to heater mode. As soon as I let up on the gas, it returns to normal operation. The a/c is cold, and blows through the upper vents again.
I have checked the recirculation door, and it is working properly. Where do I look next?
Thanks,