i have an s550 and the compressor seems like it always running. also, i have a fan noise in the cabin that is not the air conditioning.....drivng me crazy

 

Re Airmatic, you either have a faulty relay or you have a leak in the complicated system. Do the finger in the wind diagnostic approach and live with it or get the problem solved with a good scan---yes it's going to cost money!

 

That is a problem not to ignore. Been there. I would have it in the shop Monday AM. In your case, maybe the fix is simple. Mine was.

Otherwise carry a number for roadside assistance or your favorite tow truck company. Ignored, it can strand you.

Good luck.

 

Remove the B Relay from the front fuse box and check with a Multi-meter and 12V battery whether cycle. The rest should be checked with DAS scanner and a spray test.

 

That’s very odd, the pump on mine barely runs for a few seconds after the car is started it seems. My grandma’s w220 had that issue and she drove it for a long time like that. Ended up needing two front struts and a new pump because she would just drive the car with the “vehicle too low” warning on. Her excuse was “it’s a Mercedes, I’ve had them for decades. They’ve always just worked even with lights on so this should be no different right?” She was very wrong. Get that fixed ASAP or you’ll be in for an even bigger bill.

 

Any updates on this?

On our S550, it doesn't run all the time but there is a loud Pssh every couple of min or so

 

Psshh ed basmaster lol