On the 1985 car, does the tachometer work? IF not then the "klima" relay won't turn the compressor on either.
That car has an over-voltage relay to power up the EDS computer that processes the flywheel speed sensor.
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)