190E 2.3 (201.024) L4-2.3L (102.961) (1984)
Air Door Position Sensor / Switch: Adjustments
Feedback Potentiometer, Blend Air Flap
1.
Remove the instrument panel.
2.
Remove the TCC control panel.
3.
Connect the Mercedes Benz socket box or equivalent, to the control unit, plugging the harness with red adhesive tape to the lefthand connecting
plug on the control unit.
4.
Connect the positive side of a suitable voltmeter to socket 17 and ground to socket 1 of the socket box.
5.
Close the oil line for the oil pressure gauge and run the engine at idle speed.
6.
Set the temperature wheel to "MIN" and wait for approx. 60 seconds.
Potentiometer Adjusting
7a. On 1st version heater box, adjust the potentiometer to the left or right as necessary with the bridging segment on the potentiometer lever until 4 ±
0.1 volts is obtained. Adjust stop screw (51) slightly, if necessary.
Potentiometer Adjustment
7b. On 2nd version heater box, turn adjusting screw (89) to the left or right as necessary until 4 ± 0.1 volts is obtained.
8.
Set the temperature wheel to "MAX" and wait for approx. 60 seconds. The voltage should be:
0.3 - 1.2 volts
If the voltage is not attained, disconnect the vacuum element for the blend air flaps. Check the movement of the potentiometer lever. The blend air
flaps should move from "full heating" to "full cooling". Repair if needed.