Try to get a copy of owners manual on ebay or direct from MB. "EC" is
economy without air conditioner... so when EC has no red light, it is in
automatic air conditioner/heater mode.
The two temperature dial is for driver and passenger side climate control...
so if you turn it colder on your side, AC should come on... now being
winter, you might feel it, but not likely unless it is really warm outside.