Lighting Systems for GMC Truck GMC C Cab/Chassis HD (GMT 400) 2001

All Component Locator

• Lighting Systems Component Views

All Description and Operation

• Exterior Lighting Systems Description and Operation
• Interior Lighting Systems Description and Operation

All Special Tools and Equipment

• Special Tools

All Visual Identification

• Lighting Systems Connector End Views

Cleaning, Inspection, and Adjustment

• Headlamp Aiming

Diagnostic Procedures

• Backup Lamps Always On
• Backup Lamps Inoperative
• Courtesy Lamps Always On
• Courtesy Lamps Inoperative
• Daytime Running Lamps (DRL) Always On
• Daytime Running Lamps (DRL) Indicator Inoperative
• Daytime Running Lamps (DRL) Inoperative
• Daytime Running Lamps (DRL) On with Park Brake Applied
• Diagnostic Starting Point - Lighting Systems
• Hazard Lamps Inoperative
• Headlamp Low or High Beams Always On
• Headlamps Inoperative - High Beams
• Headlamps Inoperative - Low Beams
• High Beam Indicator Inoperative
• Interior Backlighting Does Not Dim
• Interior Backlighting Inoperative
• Low and High Beams Headlamps Inoperative
• Park Lamps Inoperative
• Stop Lamps Always On
• Stop Lamps Inoperative
• Symptoms - Lighting Systems
• Turn Signal Lamps and/or Indicators Always On or Flashing
• Turn Signal Lamps and/or Indicators Inoperative

Electrical/Electronic Schematic Diagrams

• Exterior Lights Schematics
• Headlights Schematics
• Headlights/Daytime Running Lights (DRL) Schematics
• Interior Lights Dimming Schematics
• Interior Lights Schematics

Mechanical Specifications

• Fastener Tightening Specifications

Removal, Installation, and Replacement

• Daytime Running Lamp (DRL) Diode Replacement
• Daytime Running Lamps (DRL) Relay Replacement
• Daytime Running Lights (DRL) Control Module Replacement
• Dome Lamp Replacement
• Door Courtesy Lamp and Reflector Replacement
• Emergency Roof Lamp Switch Replacement
• Headlamp Bulb Replacement
• Headlamp Replacement
• Headlamp Switch Replacement
• Instrument Panel Compartment Lamp Replacement
• Interior Lamp Control Module Replacement
• Parking and Turn Signal Lamp Replacement
• Roof Marker Lamp Replacement
• Tail/Turn Signal Lamp Replacement
• Underhood Lamp Replacement
• Vanity Mirror Lamp Replacement