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(WARNING)
RED MESSAGE (CAUTION)
AMBER MESSAGE (ADVISORY)
CYAN MESSAGE (STATUS)
WHITE MESSAGE Require immediate crew attention. These messages are accompanied by flashing master warning, triple chime attenson with or without voice message or dedicated tone. Require immediate crew awareness and future crew action may be required in the form of alternate system selection or performance limitation. These message are accompanied by flashing master caution and a single chime. Indicate safe or normal system operation which require crew awareness, over and above the dark cockpit philosophy. Indicate minor failures or reduction in systems capability, which require no crew action.

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06/30/21

Message Overview:

Message Name:

APU COMPARTMENT LIGHT UNSERVICEABLE

Message Code: 333OBS003
Effectivity: All
System: Service Compartment Lighting System
System Description: 33-31-00
Schematic Diagram: 33-31-00 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wiring Diagram: 33-31-02 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Message Description:

The Auxiliary Power Unit (APU) Compartment Light does not come ON.

Possible Causes:

  • Auxiliary Power Unit (APU) Compartment Light Bulb
  • Auxiliary Power Unit (APU) Compartment Light Assembly
  • Auxiliary Power Unit (APU) Compartment Light (DS58)
  • Light Switch
  • Aft Auto-Shutoff Box (A189)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Quick Links:

Electrical/Electronic Safety Precautions AMM 24-00-00-910-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Operational Test of the Aft Maintenance Lights AMM 33-31-00-710-802 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the APU Compartment Light AMM 33-31-09-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the APU Compartment Light AMM 33-31-09-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Replacement of the APU Compartment Light-Bulb AMM 33-31-09-960-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Auto-Shutoff Box AMM 33-31-17-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Auto-Shutoff Box AMM 33-31-17-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Standard Practices - System Description SPM 20-00-00-01 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Troubleshooting Recommendations:

  1. Swap the service light switch. Check if the problem is corrected.
    NOTE: This makes sure the switch is not the cause of the problem.

    1. If YES, replace the defective light switch and do close out.
    2. If NO, continue with next step.

  2. Perform the voltage check for connector of APU compartment lights as follows:

    From To Expected Result Result
    DS58-1 DS58-2 28 VDC

    1. If there is no voltage, repair or replace the defective wiring as required and do close out.
    2. If there is voltage, continue with next step.

  3. Replace the bulb of the unserviceable APU Compartment Light.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  4. Replace the APU Compartment Light Assembly.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  5. Replace AFT Auto Shutoff Boxes.
  6. Do close out.

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