This is what happened.

Last night I turned on the SEC's airconditioning, at bi-level setting, to just run it and circulate the refrigerant, having heard it is not too good to just let it be turned off for weeks at a time - in fact it had not been run for a month, although the heater and defroster were sometimes used. Well, about 1 mile down the street (heavy city stop and go traffic) I heard a single loud "click" which sounded like it came from behind the buttons on the front of the dashboard, and the airconditioning at that moment just stopped dead. I turned the button on and off but nothing happened. In fact, the fan wouldn't work at all at any speed any more. No heat, no AC, no fresh air, nothing.

Can you take a guess at what happened?. I swapped a fuse (I think it was No.5)a white one, but to no avail.

How much should this cost to fix? I am not a DIYer - at all!! My ex accountant miscalculated how much to withold so I owe a bundle of tax to Uncle Sam . so I would like to know how bad off (repair cost wise) I am with this problem. How long can I let it go--without running the Aircon before rubber bushings begin to dry up, etc. in the system? I can't let this go untended too long, I realize, because at the least I will need a defroster, since
it has been raining like crazy out here in San Francisco recently

Finally, after everything is fixed and buttoned up, what is the wisdom on using the W126 climate controls? Should I only turn on the fan and then select AC or heat when needed, or run the fan ALL THE TIME and just "dial in" the temperature I like? What would be the best thing for the car?

I'd welcome any opinions you might have.. Thank you in advance.

Best regards
Jim Baubel
1991 560 SEC

JIM,
There is a second fuse for the A/C system located in front of the main fuse box. It's called a "strip" fuse & is rated at 30AMPs.
The a/c runs when any buttons except EC or O are pushed.

Also I have seen ignition switches cause a similar problem if this problem re-occurs turn the ignition switch counter clockwise 1-2mm after the car is running. But not enough to kill the engine.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM