Originally Posted by 97 SL320

Any history on this car?

If the expansion valve was not opening enough, the high side would be going very high and low side very low / suction.

Is the large hose leading from the evaporator to the compressor cold maybe frost covered? If so , the expansion valve is working.

You might have a stuck open heater valve / blend door staying in the hot position. Feel both heater hoses, are they of equally hot temperature? If so the heaver valve is open.