New coolant temperature sensor for most Mercedes built from 1973 to 1993, Gasoline and Diesel models. Many gas models it is located on top of the thermostat housing. Sends signal to engine coolant temperature gauge on the dashboard. These are getting harder to get. Single pin
SINGLE pin - located on left side of cylinder head by glow plugs on 1977 to 1985 OM616 and OM617 Diesel engines.
Engine Coolant Temperature Sensor