Need AC Help...

[longston]

I have searched the archives, but can't find a similar enough problem that was of any help for this 1982 300SD.

Here's the problem. The AC worked fine in Oct. when I bought the car. I put it in the shop back then to have the valves adjusted and some minor work done. Then I installed a new stereo/CD. That's all that was done to the car so far.

Since then, it got hot enough to need the AC, but now, I don't get any air at all from the center vents, and I get no cold air anywhere in the car. And, the side vents don't blow as much air as they used to.

I don't have a manual, or a CD, but decided to take out the stereo this weekend to see if I has disconnected something by mistake, and to remove the center air vents to check the function of the vent control. Well, no luck so far. There is nothing that seems out of place or disconnected, and the center vent control is opening & closing the door just fine.

Also, with the engine running, and the climate controls set for maximum AC, I am getting no voltage to the wire(s) connected to the compressor.

Any suggestions or assistance would be appreciated. Where can I start to diagnose this problem?