Issue with AC

[Berglund]

Hello
I am looking for electric wiring diagram for air conditioning,
everything from pump, sensor and control panel.
sometimes my ac shuts down or it does not start up.
Clutch and compressor is ok
and refrigerant / pressure is ok, checked by "ac-doctor".
Probably a sensor that struggles?
Anyone?
Best Regards Niklas

 

[gerryvz]

I went through some struggles with my A/C system.

I would first check the electrical connection to the compressor (three pin plastic connector) to ensure that it is OK.

[SOLVED] A/C Compressor not working -- tracking down the cause | Heating and Cooling (Interior HVAC systems)

Following up on my Top-End Rebuild thread, I have driven the car around 1,700 miles since completing the job last September-ish. I have only had one problem that I've noted since I completed the job -- the A/C compressor through the fall/winter/spring has been sort of hesitant to come on. It...

www.500eboard.co

 

[Berglund]

Hi.
we now use this wiring diagram for troubleshooting, but this seems to be from -93. is there anything that is for previous year models?
Colors of cables seem to be different

 

[emerydc8]

While it is rare, this intermittent a/c compressor engagement issue could be caused by a bad base module. I chased this problem for a long time and replaced a lot of parts (compressor, receiver dryer, expansion valve, tensioner, belt, pushbutton control unit, cockpit temp sensor). Sometimes the compressor would run, but sometimes it wouldn't. If I shut the engine off and restarted, more often than not the compressor would work. If you have a spare base module to swap, you could rule that out.

 

[Sam SL]

While it is rare, this intermittent a/c compressor engagement issue could be caused by a bad base module.

I had exactly the same issue with a 95 E320 Cab

 

[gerryvz]

While it is rare, this intermittent a/c compressor engagement issue could be caused by a bad base module. I chased this problem for a long time and replaced a lot of parts (compressor, receiver dryer, expansion valve, tensioner, belt, pushbutton control unit, cockpit temp sensor). Sometimes the compressor would run, but sometimes it wouldn't. If I shut the engine off and restarted, more often than not the compressor would work. If you have a spare base module to swap, you could rule that out.

Also check the three-prong electrical connector that plugs into the top of the compressor, to ensure that the connector and wires are in good shape.