Generator Set Control Panel for Switchgear Conversion Caterpillar

Illustration 1	g00565164
Schematic For The Display Power Supply

This diagnostic code is recorded when the main display module reads a below normal voltage of the display power supply circuit. Normal display power supply voltage is 9.0 ± 0.5 DCV. The schematic that is shown above represents a typical installation of the component. Verify the connector contact and wire numbers by using the Electrical System Schematic for the engine that is being serviced.

1. Check The Voltage At The Main Display.

   1. Use the 7X-1710 Multimeter Probe Group. Check the voltage at the connector for the main display module. Measure the voltage from Contact 34 to Contact 2 (ground).

   2. DO NOT disconnect the harness from the Main Display Module.

      Expected Result: The voltage measures 9.0 ± 0.5 DCV.

      Results:

      • OK: The voltage is 9.0 ± 0.5 DCV. The display power supply voltage is correct. Check the main display module for the same diagnostic code. If the service code indicator is still ON, the main display module is faulty. Replace the module. See Testing and Adjusting, "Module - Replace". STOP.

      • Not OK: The voltage is NOT 9.0 ± 0.5 DCV. The display power supply voltage is NOT correct. Proceed to Step 2.

2. Disconnect The Display Modules.

   1. Turn the "ECS" switch to the OFF/RESET position.

   2. Disconnect the Gauge Cluster Modules.

   3. Turn the "ECS" switch to the "COOLDOWN/STOP" position.

   4. Continue to measure the voltage at the connector for the Main Display Module. Measure the voltage from Contact 34 to Contact 2.

   5. Reconnect the Gauge Cluster Modules from the engine harness one at a time. Between reconnections, measure the display's power supply voltage.

      Expected Result: The voltage that is measured is 9.0 ± 0.5 DCV.

      Results:

      • OK: The voltage is 9.0 ± 0.5 DCV. The display power supply is correct. Proceed to Step 3. STOP.

      • NOT OK: The voltage is NOT 9.0 ± 0.5 DCV after reconnecting one of the Gauge Cluster Modules. The Gauge Cluster Module that was just reconnected has a problem. Replace the Gauge Cluster Module. For more information on this subject, see Testing And Adjusting, "Module - Replace"." for a short to ground". Proceed to Step 3.

3. Check For A Short To Ground.

   1. Turn the "ECS" switch to the OFF/RESET position.

   2. Disconnect the engine harness from the main display module.

   3. Turn the "ECS" switch to the COOLDOWN/STOP position.

   4. At the engine harness connector for the main display module, measure the resistance between connector Contact 34 and Contact 2.

      Expected Result: The resistance that is measured is less than 5000 ohms.

      Results:

      • OK: The resistance is less than 5000 ohms. The engine harness is faulty. Repair the harness or replace the harness. STOP.

      • NOT OK: The resistance is greater than 5000 ohms. The harness circuit resistance is correct. The main display module is faulty. Replace the module. See Testing and Adjusting, "Module - Replace". STOP.