Defrost Flap
 

The defrost flap being open is causing condensation on my windshield with the a/c on. Very annoying when traveling at night. All other functions are normal. Any thoughts??? BTW, the r-134 retro works well. Solved my a/c belt problem by using a Contitech belt.

Thanks.

Check the defrost flap vacuum actuator. See if both chambers hold vacuum. If the acutator is good, see how much vacuum is available at the hoses when the flap should be fully closed. You can get to the actuator in a W126 by removing the glove box. I don't know about a W123.

Sixto
95 S420
87 300SDL