'99 E320 A/C won't run
 

Daughter brings home car w/tale of woe, no a/c after winter.

Basic troubleshoot shows compressor not engaging.
Seems to have a charge but I do not have proper gauges.
Do not see where fuse is for compressor, not listed on any of the 3 fuse blocks.
I assume it is in-line somewhere?
EC button is lit and will not go out when button is pressed, bad switch or more ominous?
Compressor turns by hand.

Just for giggles, I checked duo-valve. Seems fine, no hang ups.

Anything else I can check before I take to a shop?
(A/C is about the only thing I farm out, hate doing it but no tools/equipment)

Your CC Unit has built-in diagnostics. EC light almost but not always means a low charge.

Check this link for info on running diagnostics - http://www.eclassbenz.com/node/27

Best of luck.

Thanks, next time daughter is in town, I'll run error checks. Maybe even get her to do it!

Be sure to write them down and also any error codes at the end. Sometimes a little 'interpretation' is necessary.

Good luck.

Right, the EC buttom of course means "Economy", which is what you'd use to leave the compressor off. The EC light being on and not going off is a fail-safe by the ACC, sort of like being forced in to leaving the compressor off. So actually it's a "good" sign that the system is OK and yes the usuall problem is lowe on refrigerant charge.