Yes, the 85 is totally different from the earlier compressor control. The earlier 123 cars do not have a Klima relay.

The Klima relay looks at engine speed, temp, voltage, and full throttle to decide whether to fullfill its command to turn the compressor on.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician