SHAFT AS-FAN 2831654 - Caterpillar

Test Step 1. VERIFY THAT THE BACKLIGHT WILL NOT TURN OFF
Turn on the keyswitch.
Put the rocker switch in the OFF position.
Observe the backlight. Expected Result:The backlight is off.Results:
OK - The backlight is off.Repair: Resume normal operation.STOP.
Not OK - The backlight is on. Proceed to Test Step 2.Test Step 2. CHECK THE HARNESS FOR A SHORT
Turn off the keyswitch.
Disconnect all related ECMs from the harness.
Disconnect the harness from the rocker switch.
Obtain pin and wire numbers for the backlight circuit. Verify the pin and wire numbers with the machine Electrical Schematic.
Measure the resistance in the harness between the contacts for the backlight and the corresponding contacts for the ECM. Expected Result:Each resistance is greater than 5000 ohms.Results:
OK - Each resistance is greater than 5000 ohms. The backlight LED lamps may have failed.Repair: Replace the rocker switch containing the backlight LED lamps.Proceed to Test Step 3.
Not OK - A resistance is less than 5 ohms. The harness is shorted.Repair: Repair or replace the harness.Proceed to Test Step 3.Test Step 3. PERFORM AN OPERATIONAL CHECK
Reconnect all disconnected connectors.
Turn on the keyswitch.
Push the rocker switch to the ON position.
Verify that the backlight is on.
Push the rocker switch to the OFF position.
Verify that the backlight is off. Expect Result:The backlight is on when the rocker switch is on, and the backlight is off when the rocker switch is off.Results:
OK - The backlight is operating properly.Repair: Resume normal operation.STOP.
Not OK - The backlight is not operating properly. The ECM may have failed, however ECM failure is unlikely.Repair: Contact your Cat® dealer. If the ECM must be replaced, see Testing and Adjusting, "Electronic Control Module (ECM) - Replace".STOP.