HEY GUYS, I HAVE A 1989 560 SEL AND BOUGHT A HEAT MODULATOR VALVE FROM YOU THE OTHER DAY, INSTALLATION WAS STRAIGHTFORWARD AND EASY ENOUGH. THE GOOD NEWS IS I NOW HAVE PLENTY OF HEAT! THE BAD NEWS IS THE A/C HAS QUIT. WHEN THE CLIMATE CONTROL RING IS TURNED TO THE COOLING SIDE THE COMPRESSOR TURNS ON AND YOU CAN HEAR THE R-12 PUMPING THROUGH THE EXPANSION VALVE, BUT THE AIR IS NOT COLD. IS THERE A CONNECTION BETWEEN THE VALVE I REPLACED AND THE A/C SIDE? ANY SUGGESTIONS WOULD BE APPRECIATED!

Most likely it is the vacuum acuators that operate the air flappers. They tend to rot and need to be replaced. You should check each of them to be sure they hold vacuum. You will need a hand held vacuum pump/tester. The whole vacuum system for directing air needs to completely checked as well as the 7 way vacuum valve assembly which switches the vacuum to the flappers. Sometimes the valve gets plugged up. Take it out of the car and bench test each circuit for proper operation.

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I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k