0438400 JOHNSON FUEL PUMP ASSY.

Check Connectors for Moisture and Corrosion
Inspect all the harnesses. Ensure that the routing of the wiring harness allows the wires to enter the face of each connector at a perpendicular angle. Otherwise, the wire will deform the seal bore. This will create a path for the entrance of moisture. Verify that the seals for the wires are sealing correctly. Ensure that the sealing plugs are in place. If any of the plugs are missing, replace the plug. Ensure that the plugs are inserted correctly into the connector.
Illustration 1 g01131019
Seal for a three-pin connector (typical example)Disconnect the suspect connector and inspect the connector seal. Ensure that the seal is in good condition. If necessary, replace the connector.Thoroughly inspect the connectors for evidence of moisture entry.Note: It is normal to see some minor seal abrasion on connector seals. Minor seal abrasion will not allow the entry of moisture.If moisture or corrosion is evident in the connector, the source of the moisture entry must be found and the source of the moisture entry must be repaired. If the source of the moisture entry is not repaired, the fault will recur. Simply drying the connector will not fix the fault. Check the following items for the possible moisture entry path:
Missing seals
Incorrectly installed seals
Nicks in exposed insulation
Improperly mated connectorsMoisture can also travel to a connector through the inside of a wire. If moisture is found in a connector, thoroughly check the connector harness for damage. Also check other connectors that share the harness for moisture.Check the Wires for Damage to the Insulation
Carefully inspect each wire for signs of abrasion, nicks and cuts.Inspect the wires for the following conditions:
Exposed insulation
Rubbing of a wire against the engine
Rubbing of a wire against a sharp pointCheck all of the fasteners for the harness and the ECM in order to verify that the harness is correctly secured. Also check all of the fasteners in order to verify that the harness is not compressed. Pull back the harness sleeves in order to check for a flattened portion of wire. A fastener that has been overtightened flattens the harness. This damages the wires that are inside the harness.Inspect the Connector Terminals
Visually inspect each terminal in the connector. Verify that the terminals are not damaged. Verify that the terminals are correctly aligned in the connector and verify that the terminals are correctly located in the connector.Perform a Pull Test on Each Wire Terminal Connection
Illustration 2 g01237430
A typical example of the lock wedge. (1) Locking wedgeEnsure that the locking wedge for the connector is installed correctly. Terminals cannot be retained inside the connector if the locking wedge is not installed correctly.Perform the 45 N (10 lb) pull test on each wire. Each terminal and each connector should easily withstand 45 N (10 lb) of tension and each wire should remain in the connector body. This test checks whether the wire was correctly crimped in the terminal and whether the terminal was correctly inserted into the connector.Check Individual Pin Retention into the Socket
Illustration 3 g01687376
Diagram for testing pin retentionVerify that the sockets provide good retention for the pins. Insert a new pin into each socket one at a time in order to check for a good grip on the pin by the socket.Check the Locking Mechanism of the Connectors
Ensure that the connectors lock correctly. After you lock the connectors, ensure that the two halves cannot be pulled apart.Verify that the latch tab of the connector is correctly latched. Also verify that the latch tab of the connector returns to the locked position.Perform the Wiggle Test on the Caterpillar Electronic Technician (ET)
Select the "Wiggle Test" from the diagnostic tests on Cat ET.Choose the appropriate group of parameters to monitor.Press the "Start" button. Wiggle the wiring harness in order to reproduce intermittent faults.If an intermittent fault exists, the status will be highlighted and an audible beep will be heard.