Strange A/C behaviour

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,
--
Stephen Clark
89 Audi 100
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Stephen, See if the vacuum check valve is leaking - put a mity vac on the vacuum line onto the CC brain and pump it up to see if it is leaking. Cheers!
--
Steve Sears
1987 Audi 5kTQ
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Wow! that was a quick reply. Do you sit there just waiting for the questions? ( just kidding ).
And where would one find said CC brain? I don't have a manual...
Thanks for your promptness!

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Hey, what else is there to do....oh yeah...work. The "cc brain" in my '87 is located behind the glove box - follow the vacuum lines. You might want to check to see what Scott Mockry has on his new'n'improved site: www.sjmautotechnik.com Cheers!
--
Steve Sears
1987 Audi 5kTQ
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