HARNESS AS-CAB 5466076 - Caterpillar

Table 1
Troubleshooting Test Steps Values Results
1. Check the Electrical Connectors and the Wiring
A. Remove the electrical power from the Electronic Control Module (ECM).
B. Thoroughly inspect connectors. Thoroughly inspect the connections for the suspect switch. Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Perform a 45 N (10 lb) pull test on each of the wires in the circuit for the suspect switch.
D. Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
E. Check the harness and wiring for abrasions and for pinch points from the battery to the ECM.
All connectors, pins, and sockets are coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion and of pinch points.
Result: The wiring and connectors appear to be OK.
Proceed to Test Step 2.
Result: There is a problem with the wiring and/or a connector.
Repair: Repair the wiring and/or the connector. Replace parts, if necessary. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.
STOP
2. Test the Switch for Proper Operation
A. Disconnect the P1 connector.
B. Refer to Table 2. Determine the P1 terminal for the suspect switch.
C. Connect one lead of a multimeter to the P1 terminal for the suspect switch. Connect the other lead of the multimeter to negative ground.
Note: Wiggle the harnesses during the following measurements to reveal any intermittent short condition.
D. Measure the resistance between the P1 terminal for the suspect switch and negative ground.
E. Activate the switch and measure the resistance again.
One resistance measurement indicates an open circuit. The other resistance measurement indicates that a short circuit exists.
Result: One resistance measurement indicates an open circuit. The other resistance measurement indicates that a short circuit exists.
Repair: The switch is operating correctly. The wiring does not have a short circuit or an open circuit. Operate the engine and check the switch for proper operation. If the switch does not operate correctly, there may be a short circuit between the circuit for the suspect switch and another circuit. Carefully reinspect the components. Refer to Troubleshooting, "Electrical Inspectors - Inspect". Locate the short circuit and perform repairs.
STOP
Result: Both resistance measurements indicate an open circuit or both resistance measurements indicate a short circuit.
Repair: There is a problem with the circuit for the switch. The problem could be in the switch, in the wiring, or in a connector. Carefully reinspect the components. Refer to Troubleshooting, "Electrical Inspectors - Inspect" for information that relates to troubleshooting suspect electrical problems in the harness. If the inspection does not identify the faulty component, replace the switch and test the switch again. If the problem is not resolved, repair the wiring or the connector. Replace parts, if necessary. Verify that the problem is resolved.
STOP