The compressor should shut off when depressinf the EC OR "0" buttons. IF not someone has wired the compressor to run all of the time.
Heat is controlled by the heater valve assembly(duo-valve) about a foot behind the left headlight, under a black plastic cover.
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)