03-07-2005, 07:24 AM
Date registered: Feb 2005
1993 400SEL AC issues
The AC on this car cycles on and off.
I connected a gauge manifold to it and the high pressure side pressure rises and then the ac compressor clicks off. Then the pressure falls and the compressor clicks on.
Obviously some pressure switch is preventing excessive pressures on the high side
As far as I recall, the high side carries gas from compressor to the condensor to be made into liquid and then to the evaporator to be passed thru the expansion valve and be converted into gas once again-cooling the evaporator and the interior of the car in the process. The low side carries this hot gas to the compressor.
So I think something in the high side is rectricted. Could be the expansion valve or the condensor or the filter.
Anyone with similar problems?