A week or so ago, I diagnosed that the likely cause of my non functional A/C in the 300SE was the W126 Klima relay. The second generation W126 went to a Klima relay to control the A/C compressor.
The W126 Klima relay is more of a control unit than a simple relay. It has multiple inputs that determine if the A/C compressor should not engage. These include:
During full throttle When the engine is very hot Invalid compressor speed (e.g slipping belt) Not enough coolant in the system
This additional functionality makes these relays more sensitive than the little silver […]
