The EC switch is the econo switch for switching the aircon off - has nothing to due with low aircon gas. If your fan/blower rotary switch is in the O "off" position then the aircon will be switched off, as well the air flap will also be in the closed position. The funny noises you hear will be the air flaps modules working, maybe they are leaking also. Iam not sure why the vacuum pumpwold be running, possibly a leak there also.
regards

On many of the MB A/C systems, the system will go into EC mode if there is a fault in the system, be it low pressure (protecting the compressor) or a sensor fault. If the EC engages on its own, it's a sure sign that the system is faulting somewhere.

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

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Thank you guys
Looks like i will start with making sure that sytem has enough R134a, then if problem persists a dash removal will be scheduled.

Uh, why? Do you have a diagnosis?

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif