SHAFT 4C1815 - Caterpillar

Illustration 1 g00646473
(1) Actuator motor (upper body) (2) Actuator motor (lower) (3) Actuator motor (recirculated air or fresh air) (4) Actuator motor (water valve) (5) Control module (6) Speed control (7) Connection to control panel (6 pin) (8) Connection to cab harness (8 pin)
Locate the air damper that is not functioning properly. Refer to Illustration 1 for the location of actuator motors.
Turn the engine start switch to the ON position. Do not start the engine.
Disconnect the questionable actuator motor at the air conditioner and heater group.
Press the air outlet switch on the control panel that controls the questionable actuator motor.
Monitor the supply voltage and monitor the ground at the connector for the actuator motor.
If voltage (12 V) is present for 10 to 25 seconds, connect the actuator motor and retest the actuator. If the actuator does not turn properly, the actuator should be replaced.
If voltage (12 V) is not present, proceed to step 7.
Perform a check of the control panel at electrical connection (7) . Refer to Testing and Adjusting, "Control Panel - Test".
If the check of the control panel is successful, proceed to step 8.
If the check of the control panel is not successful, replace the control panel.
Check continuity on the signal wire and the ground wire between the control module and the actuator motor.
If continuity exists on both wires, replace the control module.
If continuity does not exist on both wires, repair the bad wire. If the bad wire is not repairable, replace the control module.