300E (124.030) L6-3.0L (103.983) (1986)
Radiator Cooling Fan Temperature Sensor / Switch: Description and Operation
Coolant Temperature Switch (S25/5)
PURPOSE
The 105/115°C temperature switch, activates the auxiliary fan via the high speed relay, and deactivates the compressor clutch via the compressor cut-out
control unit to prevent engine overheat.
LOCATION
The 105/115°C temperature switch is located on the intake side of the cylinder head.
OPERATION
At coolant temperatures of approx. 221°F (105°C), the temperature switch completes the ground circuit for the high speed fan relay, activating the
auxiliary fan (high speed). As the temperature drops below approx. 206°F (97°C) the circuit is opened and fan operation discontinues.
At coolant temperatures of approx. 239°F (115°C), the temperature switch disengages the A/C compressor via a ground signal to the compressor cut-out
control unit. As the temperature drops below approx. 226°F (108°C) the temperature switch circuit is opened, reactivating the compressor.