1998 SL500 R129 Climate Control No A/C

[dproudfo]

Hi All:

Having an issue I'm a little stumped on where to start diagnosing next. As it is now, the climate control unit works for heating the car just fine but no A/C, no engaging of the compressor. Refrigerant levels are low but still should be enough to run. The 1 thing is that I'm unable to activate forward direction airflow as well. Ran the codes with Xentry and came up with the following:

KLA Fault Memory
B1416 Heating water circulation pump; A31m1
B1232 Refrigerant pressure sensor; B12
B1233 Refrigerant temperature sensor; B12/1
B1228 Left heat exchanger temperature sensor; B10/2
B1230 Evaporator temperature sensor B10/6
B1233 Refrigerant temperature sensor B12/1
B1226 In-car temperature sensor B10/4

Of these I can't clear any so I took a shot at the Evap Temp Sensor replacement and still have the same issue. Ran sensor values direct from the Climate Control unit and the errors from the Xentry Fault Memory are all reading OPE showing open circuit on the control unit which was my suspicion of a domino effect from either fuse/relay vs all of these sensors being bad. Fuses look good but a not sure about any relays directly affecting only these sensors. (or if 1 of these sensors is the culprit for the remainder)

Any help would be much appreciated! Thanks in advance for your time.