ReferenceSpecial Instruction, SEHS9065, "Use Of CE Connector Tools".
ReferenceService Magazine, SEPD034227 January 97, "Field Repair Of Single Wire Breaks In Harnesses (Sealed Splice)".
ReferenceService Magazine, SEPD037128 July 97, "Protection Of Unsealed Electrical Terminations For Machines In Corrosive Applications".
ReferenceService Magazine, SEPD047324 May 99, "New DT Connector Plugs With Improved Seal Retention".
ReferenceService Magazine, SEPD054509 October 00, "Dielectric Grease Should Not Be Used In Electrical Connectors".
This information will assist in detecting problems with connectors and with wiring. If a problem is found, correct the condition and verify that the problem is resolved.
Disconnecting and reconnecting connectors sometimes resolve intermittent electrical problems. Checking for diagnostic codes immediately before disconnecting a connector is important. Also check for diagnostic codes after reconnecting the connector.
If the status of a diagnostic code is changed due to disconnecting and reconnecting a connector, there are several possible reasons. The likely reasons are loose terminals, improperly crimped terminals, moisture, corrosion, and inadequate mating of a connection.
Important Safety Information
Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.
A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.
Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.
Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. Make sure that all tools, procedures, work methods, and operating techniques are safe for all people. This applies even if the tools, procedures, work methods, and operating techniques that are used are not recommended by Caterpillar.
Make sure that the product will not be damaged or be made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.
Guidelines
- Always use a 1U-5804 Crimp Tool (12-GA TO 18-GA) to service Deutsch HD and DT connectors. Never solder the terminals onto the wires. Refer to Tool Operating Manual, SEHS9615, "Servicing Deutsch HD and DT Style Connectors".
- Always use a 147-6456 Wedge Removal Tool in order to remove wedges from DT connectors. Never use a screwdriver to pry a wedge from a connector.
- Always use a breakout harness for a voltmeter probe or a test light. Never break the wire insulation to access a circuit for measurements.
- If a wire is cut, always install a new terminal for the repair.
Some minor seal abrasion on connector seals is normal. 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 repaired. If the source of the moisture entry is not repaired, the problem will recur. Simply drying the connector will not fix the problem. Check the following items for the possible moisture entry path:
Moisture 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 all of the remaining connectors on the harness for moisture.
The plug end of the DT connector has a replaceable seal at the mating end of the connector. This seal has been improved on black connectors to help prevent slipping and to help keep moisture and dirt from entering the connector.
The current seal design (2) is not interchangeable with the former design (1). The receptacle has also changed to the new colors.
 | |
| Illustration 1 | g01960176 |
(3) Seal for a three-pin connector (typical example) | |
 | |
| Illustration 2 | g02732798 |
(4) Locking Wedge for 3-pin connector | |
 | |
| Illustration 3 | g01960167 |
(1) Former Seal Design (2) Current Seal Design | |
Tests
| Troubleshooting Test Steps | Values | Results |
|---|---|---|
| 1. Inspect All Wiring Harnesses A. 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 condition will create a path for the entrance of moisture. B. Verify that the seals for the wires are sealing correctly. C. Disconnect the suspect connector and inspect the connector seal. Ensure that the seals are in good condition. If necessary, replace the connector. D. Thoroughly inspect the connectors for evidence of moisture entry. E. Check the following items for a possible moisture entry path: missing seals, improperly installed seals, nicks in exposed insulation, and improperly mated connectors. |
The harness wiring, connectors, and seals are in good condition. There is no evidence of moisture in the connectors. |
OK - The harness wiring, connectors, and seals are in good condition. Proceed to Test Step 2. NOT OK - A problem has been found with the harness or the connectors. Repair: Repair the connectors or the wiring as required. Ensure that all of the seals are properly in place. Make sure that the connectors have been reattached. If corrosion is evident on the pins, sockets, or the connector, use only denatured alcohol to remove the corrosion. Use a cotton swab or a soft brush to remove the corrosion. If moisture was found in the connectors, run the engine for several minutes and check again for moisture. If moisture reappears, the moisture is wicking into the connector. Even if the moisture entry path is repaired, replacing the wires may be necessary. Verify that the repair eliminates the problem. STOP |
| 2. Check The Wires For Damage To The Insulation A. Check all of the fasteners to verify that the harness is secure and is NOT compressed. B. Pull back the harness sleeves to check for a flattened portion of wire. A fastener that has been overtightened will flatten the harness. C. Carefully inspect each wire for signs of abrasion, nicks, or cuts. Inspect the wires for the following conditions: exposed insulation, rubbing of a wire against the chassis, or rubbing of a wire against a sharp point. |
The wires are free of abrasion, nicks, or cuts. The harness is properly clamped. |
OK - The harness has passed all checks. Proceed to Test Step 3. NOT OK - There is damage to the harness. Repair: Repair or replace the wires as required. Verify that the repair eliminates the problem. STOP |
| 3. Visually Inspect Each Connector Terminal A. Verify that the terminals are not damaged. Verify that the terminals are properly aligned and properly located in the connector. |
The terminals are properly aligned and the terminals appear undamaged. |
OK - The terminals show no signs of damage. Proceed to Test Step 4. NOT OK - The terminals of the connector are damaged. Repair: Repair and/or replace the terminals as required. Verify that the repair eliminates the problem. STOP |
| 4. Perform a Pull Test on Each Wire Terminal Connection A. Ensure that the locking wedge for the connector is installed properly. Refer to Figure 2. B. 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. Each wire should remain in the connector body. |
The wire was properly crimped in the terminal and the terminal was properly inserted into the connector. |
OK - All terminals pass the pull test. Proceed to Test Step 5. NOT OK - A wire has been pulled from a terminal or a terminal has been pulled from the connector. Repair: Use the 1U-5804 Crimp Tool (12-GA to 18-GA) to replace the terminal. Replace damaged connectors as required. Verify that the repair eliminates the problem. STOP |
| 5. Check Pin Retention For Each Individual Socket A. Disconnect the harness. B. Insert a new pin into each socket of the mating plug. Check for a good grip on the pin by the socket. |
The sockets provide good retention for the new pin. |
OK - The terminals are OK. Proceed to Test Step 6. NOT OK - Terminals are damaged. Repair: Use the 1U-5804 Crimp Tool (12-GA to 18-GA) to replace the damaged terminals. Verify that the repair eliminates the problem. STOP |
| 6. Check Locking Mechanism Of The Connectors A. Lock the mating connectors together. Make sure that the two halves cannot be pulled apart. B. Verify that the latch tab of the connector is properly latched. Also, verify that the latch tab of the connector returns to the locked position. |
The connectors lock securely. No cracks or breaks are found at the connectors. |
OK - The connectors are in good condition. Proceed to Test Step 7. NOT OK - A connector locking mechanism is damaged or missing. Repair: Repair the connector or replace the connector as required. Verify that the repair eliminates the problem. STOP |
| 7. Perform The Wiggle Test On Cat® Electronic Technician (Cat ET) Service Tool A. Select the Wiggle Test from the diagnostic tests on Cat ET. B. Choose the appropriate group of parameters to monitor. C. Press the "Start" button. Wiggle the wiring harness in order to reproduce intermittent problems. D. If an intermittent problem exists, the status will be highlighted and an audible beep will be heard. |
No intermittent problems were indicated during the Wiggle Test. |
OK - No intermittent problems were found. The harness and connectors appear to be OK. If another procedure recommended this test, return to that procedure and continue testing. If the problem has been resolved, return the machine to service. STOP NOT OK - At least one intermittent problem was indicated. Repair: Repair the harness or the connector. Verify that the repair eliminates the problem. STOP |