PLATE 3026223 - Caterpillar

resistance measurement, wiggle the machine harness connector for the generator ECM and wiggle the machine harness connector for the Power Inverter. Gently pull on the wires and move the wires around. Do not disconnect the jumper wire.Expected Result:The resistance measurement is less than 5.0 ohms at all times during the manipulation of the harness and connectors.Results:
OK - The resistance measurement is less than 5.0 ohms. The resistance measurement is not indicating an open or a bad connection in the circuit. Proceed to Test Step 4.
NOT OK - The resistance measurement is greater than 5.0 ohms at all times or the resistance measurement is greater than 5.0 ohms some of the time during the manipulation of the harness. The resistance measurement is indicating an open circuit or a bad connection in the machine harness.Repair: The open circuit or the poor connection is in one of the sensor circuits that is connected by the jumper wire.A problem in the sensor return circuit will result in active diagnostic codes for all three of the Generator current sensors.Verify that the jumper wire is making good contact at both of the connection points.Examine the pins on the Generator ECM J2 connector that are used for the current sensor connections again. Examine the pins on the Power Inverter 70 pin connector that are used for the current sensor connections again. Verify that the connections at the connectors are not causing the problem.Measure the resistance of the circuits again. If the same result is found, the machine harness has failed.The machine harness is a sealed harness. This harness is not serviceable. Replace the machine harness.Refer to the complete machine Electrical System Schematic in order to determine the part number for the machine harness.After the new machine harness has been installed, ensure that the problem has been corrected before operating the machine.STOPTest Step 4. CHECK THE SENSOR CIRCUIT FOR A SHORTThe key switch and the disconnect switch remain in the OFF position.The machine harness connectors for the 70 pin Power Inverter connector and the Generator ECM J2 connector remain disconnected.
Disconnect the machine harness connector J2 from the Motor ECM.
Inspect the short harness for any areas where the insulation is worn. Inspect the harness for pinch points that could cause a short circuit.
At the machine harness 70 pin connector for the Power Inverter, measure the resistance between the sensor signal contact 69 (wire N844-BU) and frame ground. Measure the resistance between the sensor signal contact 69 (wire N844-BU) and each of the other contacts that are used on the 70 pin connector for the Power Inverter.Expected Result:Each of the resistance measurements between the sensor circuit, frame ground and all of the other circuits that are used in the harness is greater than 5000 ohms.Results:
OK - Each of the resistance measurements is greater than 5000 ohms. The resistance measurements are indicating that the current sensor circuits are not shorted to another circuit or to frame ground in the machine harness. Proceed to Test Step 5.
NOT OK - At