Intermittent A/C Clutch - A Relay, perhaps??? - PeachParts Mercedes-Benz Forum

speace · #3 04-09-2008, 08:13 AM

Quote:

Originally Posted by M.B.DOC

The "MAS" relay engages the a/c compressor on that car.

Could be several problems that cause the compressor NOT to come on.

The a/c controller (pushbutton) sends ground signal to that relay thru the low pressure switch on the drier. Checking for that ground signal would be MY starting point.

Thanks!

I see two switches at the drier. One appears to be a traditional A/C low-pressure switch (EDIT: S31) and is ON the drier. The other is green plastic and I think was on a fitting right AT the drier. Would the green one be a temperature switch? (EDIT: The Green one is a pressure switch [S32] that turns on the AUX FAN)

I will find a way to test at the pressure switch. It is good to know I am looking for a ground there from the Climate Controller.

Where is the MAS relay? I may want to examine it for bad solder joints.