AC compressor and bower motor cutting out - PeachParts Mercedes-Benz Forum

obeygnt52074 · #1 09-02-2012, 03:19 PM

I have an 81 300d. When I accelerate the compressor clicks off and the blower motor stops. When I stop at a stop light it all comes back on. The only thing I can think of is a high pressure issue. I have a decent understanding of AC systems, but I'm not 100% on how the controls on these cars work. any help would be appreciated, thanks.

SD Blue · #2 09-03-2012, 10:23 AM

It is doubtful that the blower would be cutting out due to a pressure problem. I would think the pushbutton controller would be the more likely suspect, common to both. This sounds more like intermittent solder joints inside the pushbutton controller. The circuit boards are arranged in an "H" pattern and the solder joints can crack where the boards meet. Fortunately, not a difficult repair.

obeygnt52074 · #3 09-05-2012, 08:13 PM

Yeah, I went to my garage and dug out my gauges, the pressure is decent. I removed the control unit and the circuit board was really hot, I do live in Vegas, but it doesn't seem like it should be that hot. I checked the soldering and it all looks ok. I do have bad motor mounts and the car shakes pretty bad, it probably rattled something loose. I might just try to find a used one.

JHZR2 · #4 09-06-2012, 12:19 AM

Doesnt the aux water pump pull current through the control board? If you feel heat, check your aux pump to make sure it isnt pulling current and burning up your board.