Originally Posted by Benzmeister

I also have a vacuum pump and tested the pods or rubber diaphrams and they all worked the way they should. I had a buyer looking at the car yesterday, he told me of a private Mercedes shop in a nearby town that works on these HVAC systems. The guy has a 76, 81 SLC's and a 95 SL500 He took my 79 for a hours ride and when he returned he said this is one of the best running SLC's he has driven. Now if I could only get the HVAC to work. I did fix the vacuum leak on the passenger side. The vacuum was leaking back to the tank I put one of the blue and black thing in line on the blue vacuum hose now the door lock, gas door lock trunk lock all work. I checked in the shop manual on the HVAC, the vacuum for the HVAC is supposed to come directly off the engine, a white vac tube from the main vacuum distribution point. Can find this vacuum tube/line on my car?

PS: The guy who test drove my car is thinking about buying it as is. He said aside from the HVAC the car is in great shape, better then his other two and for what I am asking for it, its a steal.