Mercedes: Air conditioning, mercedes benz 300e, airconditioning system

Question
I have a 1986 300e. The airconditioning system was not wrking. I have since replaced the blower motor which now works well. I have had the  system fully recharged. Te mehanic placed 2.4 lbs of  gas in the system . The mechanic checked for leaks and was able to determine that the system was not leaking. He recharged the system with r12 gas.
Once the system wa reharged we started the system and turned inthe air conditoioner.
The system coctinued ot pump out hot air. Teh tempture gaage on the dash continued to drop as the system was running. However, air entering the  cabin through the ducts is very hot. The auxillary fan runs and the  comnperessor turns on when I tunr the dial to  it s lowest setting. A touch of the airconditoining  hose indicates that this is cold.
However the  hose that runs along the passenger side fender remains hot.
csan you tell what is the next step to determine what is wrong and how to repair the problem?


Answer
Best guess:
Bad ACC Mono Valve.

PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1986 Mercedes Benz 300E
Part: ACC Mono Valve
 Note:  Heater Valve
With heating water feed in top of heater core. Electromagnetic heater valve.     
 Year: -3/1990
R3022-11894 ACC Mono Valve IN STOCK $144.06  

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