Pump Electronic Monitoring System for Well Stimulation Pumps Caterpillar

Most electrical problems are caused by poor connections. The following procedure will help in detecting problems with connectors and with wiring. If a problem is found, correct the condition and verify that the problem is resolved.

Intermittent electrical problems are sometimes resolved by disconnecting and reconnecting connectors. Check for diagnostic codes immediately before disconnecting a connector. 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.

Follow these guidelines:

• Always use a 1U-5804 Crimp Tool to service Deutsch HD and DT connectors. Never solder the terminals onto the wires. Refer to "SEHS9615, ServicingDeutsch HD and DT Style Connectors".

• Always use a 147-6456 Wedge Removal Tool 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 insulation of a wire to access to a circuit for measurements.

• If a wire is cut, always install a new terminal for the repair.

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The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.

1. Determine If The Problem Is Intermittent.

   If the problem is intermittent, attempt to test the circuit before you disconnect any electrical connectors. Testing the circuit helps identify the root cause of intermittent problems.

   The "Wiggle Test" on the Cat^® Electronic Technician (ET) may be able to test the circuit. Refer to the documentation that accompanies Cat ET.

   Perform the wiggle test on the circuit, when possible. Otherwise, continue with this procedure.

2. Check the Connectors for Moisture and For Corrosion.
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   Illustration 1	g01131211
   Detail A illustrates the incorrect angle of wire entry into the connector. The wire should enter the connector at a perpendicular angle. (typical example)

   1. Inspect all wiring 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. Refer to Illustration 1. deforming the seal bore will create a path for the entrance of moisture. Verify that the seals for the wires are sealing correctly.
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      Illustration 2	g01131276
      Diagram for the installation of a connector plug (typical example) (1) Electronic Control Module (ECM) connector (2) Correctly inserted plug (3) Incorrectly inserted plug

   2. 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. Refer to Illustration 2.
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      Illustration 3	g01131019
      Seal for a three-pin connector (typical example)

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      Illustration 4	g01131165
      Seal for ECM connector (typical example)

   3. Disconnect the suspect connector and inspect the connector seal. Ensure that the seals are in good condition. If necessary, replace the connector.

   4. Thoroughly inspect the connectors for evidence of moisture entry.

      Note: 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. The source of the moisture entry must then be 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:

      • Missing seals

      • Improperly installed seals

      • Nicks in exposed insulation

      • Improperly mated connectors

      Moisture can also travel to a connector through theinside awire. If moisture is found in a connector, thoroughly check the connector harness for damage. Also check other connectors that share the harness for moisture.

      Note: The ECM is a sealed unit. If moisture is found in an ECM connector, the ECM is not the source of the moisture. Do not replace the ECM.

3. Check the Wires for Damage to the Insulation.

   1. Carefully inspect each wire for signs of abrasion, of nicks, and of cuts.

      Inspect the wires for the following conditions:

      • Exposed insulation

      • Rubbing of a wire against the engine

      • Rubbing of a wire against a sharp point

   2. Check all the wiring harness fasteners to verify that the harness is properly secured. Also check all the fasteners to verify that the harness is not compressed. Pull back the harness sleeves 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.

4. Inspect the Connector Terminals.

   Visually inspect each terminal in the connector. Verify that the terminals are not damaged. Verify that the terminals are properly aligned in the connector and verify that the terminals are properly located in the connector.

5. Perform a Pull Test on Each Wire Terminal Connection.
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   Illustration 5	g01131435
   Receptacle lock wedge (typical example)

   1. Ensure that the locking wedge for the connector is installed properly. Terminals cannot be retained inside the connector if the locking wedge is not installed properly.

   2. 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 properly crimped in the terminal and whether the terminal was properly inserted into the connector.

6. Check Individual Pin Retention into the Socket.
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   Illustration 6	g01131604
   Diagram for testing pin retention (typical example)

   1. Verify that the sockets provide good retention for the pins. Insert a new pin into each socket one at a time to check for a good grip on the pin by the socket.

7. Check the Locking Mechanism of the Connectors.

   1. Ensure that the connectors lock properly. After locking the connectors, ensure that the two halves cannot be pulled apart.

   2. 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.

8. Check the Allen Head Screws on the Connectors.

   Visually inspect the allen head screws for the ECM connectors. Ensure that the threads on each allen head screw are not damaged.

   1. Connect the ECM connectors.
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      Illustration 7	g01132849
      Allen head screw for the 70-pin ECM connector (typical example)

   2. Torque the allen head screw for the 70-pin ECM connector to 6.0 + 1.5 - 1.0 N·m (55 + 13 - 9 lb in).

9. Perform the Wiggle Test on the Cat ET

   1. Select the "Wiggle Test" from the diagnostic tests on Cat ET.

   2. Choose the appropriate group of parameters to monitor.

   3. Press the "Start" button. Wiggle the wiring harness to reproduce intermittent faults.

   4. If an intermittent fault exists, the status will be highlighted and an audible beep will be heard.