cybertronicify

Got another question. Does my car, 2003 S430, have a clutched A/C compressor or a Variable Displacement compressor? I'm seeing mixed answers from people. Some say Mercedes changed to VDC back in 1996 and I'm seeing replacement compressors that contains a clutch.

wallyp

I think that it is both - a variable displacement compressor that can be turned off.

cybertronicify

hmm it does make sense to put a clutch on it since even at the lowest setting it's still spinning. Wally how confident are you with your answer?

wallyp

Not very, as it turns out.

Per Mercedes-Benz publication 507 HO HVAC W220 (ACB, IC) 10-30-02, Page 34:
"The A/C compressor volume is varied between 2% (minimum stroke volume) and 100% (max. stroke volume) by the control flow via the externally controlled A/C compressor control valve (1)."

On Page 36:
"A/C Compressor Drive Pulley" "No electro-magnetic clutch"
This is accompanied by an illustration of the pulleys and belts, with the drive pulley circled.

On Page 37:
"A/C Compressor Pulley (Rubber Coupling)"
This is accompanied by an illustration of the rubber drive elements, the hub and the pulley.

I think that we can take this as definitely proven...

cybertronicify

So wally, you are saying that it does indeed have a variable displacement compressor? I didn't quite get your last post. Where can I find the information you provided? Is it a service manual?

wallyp

I gave you the full identification number of what appears to be a detailed training or description manual on the W220 HVAC system, and gave you direct quotes from the manual. I printed it from an internet source - no idea of where I got it several years ago.

Google is your friend...

cybertronicify

Okay wally, thank you for the help. Yes it does indeed have a variable displacement compressor for anyone who comes for a fast answer. Here is the pdf if anyone is curious.

http://wenku.baidu.com/view/b0f34432...b6f1a10fe.html

I like how they use a rubber coupling as a fail safe just in case the compressor seizes up.