I have been chasing a warm up idle speed problem in my 1985 500SE. This has been hampered by the absence of a definitive wiring diagram. Local dealer supplied diagram of CIS-E; which does not match my setup.
The problem is low erratic idle with stumbles and stalls; which occurs after a problem free startup and when the temp gauge shows 40degs c to 60degs c. At approx 60degs c idle speed rises to a smooth idle as if a switch had been thrown.
Could someone give me the location of the coolant temp. sensor on this model and the expected electrical resistance.