ALTERNATOR GP-CHARGING 1251412 - Caterpillar

Operation Description:The parking brake solenoid has no diagnostics for checking for faults in the system. The solenoid will NOT be energized when there is an open circuit or a short to ground. If the parking brake solenoid is shorted to the +battery the solenoid will be ON all the time.Test Step 1. CHECK FOR HYDROSTATIC OPERATION
Occupy the seat.
Lower the armrest.
Turn the key start switch to the ON position.
Press and release the parking brake switch.Expected Result:The hydrostatic system should energize.Results:
OK - The hydrostatic system energizes. Proceed to Test Step 2.
NOT OK - The hydrostatic system does NOT energize.Repair: See Troubleshooting, "Switch (Parking Brake)". Stop.Test Step 2. CHECK VOLTAGE AT THE SOLENOID VALVE WITH KEY SWITCH OFF
Turn the key start switch to the OFF position.
Locate the parking brake solenoid under the cab.
Disconnect the parking brake solenoid from the electrical connector.
Measure the voltage across the two contacts of the harness connector (A958-WH and G939-YL).Expected Result:The voltage should be less than 2 DCV.Results:
OK - The voltage is less than 2 DCV. Proceed to Test Step 3.
NOT OK - The voltage is greater than 2 DCV.Repair: The wire harness is shorted to a + battery circuit. Repair the wire harness or replace the wire harness. Stop.Test Step 3. CHECK VOLTAGE AT THE SOLENOID VALVE WITH KEY SWITCH ON
Turn the key start switch to the ON position.
Measure the voltage across the two contacts of the harness connector (A958-WH and G939-YL).Expected Result:Voltage should be less than 2 DCV.Results:
OK - The voltage is less than 2 DCV. Proceed to Test Step 4.
NOT OK - The voltage is greater than 2 DCV. Proceed to Test Step 6.Test Step 4. CHECK THE VOLTAGE AT THE SOLENOID VALVE WHILE THE KEY SWITCH IS ON AND THE PARKING BRAKE IS RELEASED
Turn the key start switch to the ON position. Press and release the parking brake switch.Note: Two people will need to perform this procedure. One person will need to be sitting in the seat with the armrest in the DOWN position.
Measure the voltage across the two contacts of the harness connector (A958-WH and G939-YL).Expected Result:The voltage should be greater than 10 DCV.Results:
OK - The voltage is greater than 10 DCV. Proceed to Test Step 5.
NOT OK - The voltage is less than 10 DCV. Proceed to Test Step 7.Test Step 5. CHECK RESISTANCE OF THE SOLENOID
Measure the resistance between the two wires of the parking brake solenoid.Expected Result:The resistance should be 10 2 Ohms.Results:
OK - The resistance is 10 2 Ohms.Repair: The problem does NOT appear to be electrically related. Stop.
NOT OK - The resistance is NOT 10 2 Ohms.Repair: The solenoid has failed. Replace the solenoid. Stop.Test Step 6. CHECK THE WIRE HARNESS FOR A SHORT CIRCUIT
Locate the Interlock ECM.
Disconnect the wire harness.
Turn the key start switch to the ON position.
Check the resistance from contact 13 of the wire harness to the following contacts: contact 1, contact 11, contact 24, contact 29, contact 62 and contact 70.Expected Result:The resistances should be above 2 Ohms.Results:
OK - The