ALTERNATOR GP-CHARGING 1251410 - Caterpillar

Illustration 1 g01032879
Fuse panel
Locate the fuse panel on the back side of the operator's station. See Illustration 1.
Remove the gauge fuse and inspect the gauge fuse.Expected Result:The fuse should be good.Results:
OK - The fuse is good. Proceed to Test Step 2.
NOT OK - The fuse is bad.Repair: Replace the fuse. Stop.Test Step 2. CHECK FOR POWER AT THE INDICATOR MODULE
Disconnect the wire harness from the warning indicator module.
Turn the key start switch to the ON position.
Measure the voltage from contact 1 (wire 123-WH) to machine ground.Expected Result:Voltage should be greater than 10 DCV.Results:
OK - Voltage is greater than 10 DCV. Proceed to Test Step 3.
NOT OK - Voltage is less than 10 DCV.Repair: The wire harness has failed. Repair the wire harness and/or connectors or replace the wire harness and/or connectors. Stop.Test Step 3. CHECK THE GROUND WIRE ON THE INDICATOR MODULE
Turn the key start switch to the ON position.
Measure voltage from contact 1 to contact 2 (wire 123-WH to 200-BK).Expected Result:Voltage should be greater than 10 DCV.Results:
OK - Voltage is greater than 10 DCV. Proceed to Test Step 4.
NOT OK - Voltage is less than 10 DCV.Repair: The ground wire is faulty in the wire harness. Repair the wire harness and/or connectors or replace the wire harness and/or connectors. Stop.Test Step 4. CHECK FOR POWER TO THE PARKING BRAKE INDICATOR.
Turn the key start switch to the ON position.
Measure voltage from contact 1 to contact 4 (wire 123-WH to wire 674-BU) of the wiring harness for the warning indicator module.Expected Result:Voltage should be greater than 10 DCV.Results:
OK - The voltage is greater than 10 DCV. Proceed to Test Step 6.
NOT OK - The voltage is less than 10 DCV. Proceed to Test Step 5.Test Step 5. CHECK THE WIRE FROM THE ECM TO THE INDICATOR MODULE (PARKING BRAKE INDICATOR)
Turn the key start switch to the OFF position.
Raise the cab. See Operation and Maintenance Manual, "Cab Tilting".
Locate the interlock ECM. The interlock ECM is located on the left side of the machine beneath the access cover on the floor of the machine.
Remove the wire harness from the ECM.
Measure the resistance from contact 70 to contact 4 (wire 674-BU to wire 201-BK) of the wire harness connector.Expected Result:The resistance should be approximately 75 Ohms.Results:
OK - The resistance is approximately 75 Ohms.Repair: The ECM is very unlikely to have failed. Reconnect all connections and visually inspect the wire harness. Verify that the diagnostic code still exists. If the diagnostic code still exists perform the Test Steps again.Replace the ECM, if the cause of the diagnostic code was not found after the second attempt. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". Stop.
NOT OK - The resistance is not approximately 75 Ohms.Repair: The wire harness has failed. Repair the wire harness and/or connectors or replace the wire harness and/or connectors. Stop.Test Step 6. CHECK FOR POWER TO THE ARMREST INDICATOR.
With the armrest in the UP position, turn the key start switch to the ON position.
Measure voltage from contact 1 to contact