Symptoms - Lighting Systems. GMC Truck TopKick C-Series (Conventional) C6/C7/C8 2006

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2006 🢒 TopKick C-Series (Conventional) C6/C7/C8 🢒 General Information 🢒 Vibration Diagnosis and Correction 🢒 Symptoms - Lighting Systems

Important: Review the system operation in order to familiarize yourself with the system functions. Refer to :

•	Exterior Lighting Systems Description and Operation

•	Interior Lighting Systems Description and Operation

•	Inspect for aftermarket devices which could affect the operation of the Lighting System. Refer to Checking Aftermarket Accessories .

•	Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

•	Backup Lamps Always On

•	Backup Lamps Inoperative

•	Daytime Running Lamps (DRL) Indicator Inoperative

•	Daytime Running Lamps (DRL) Inoperative

•	Dome Lamps Always On

•	Dome Lamps Inoperative

•	Hazard Lamps Inoperative

•	Headlamps Inoperative - Low Beams

•	Headlamps Inoperative - High Beams

•	Low and High Beams Headlamps Inoperative

•	High Beam Indicator Inoperative

•	Interior Backlighting Does Not Dim

•	Interior Backlighting Inoperative

•	Marker Lamps Always On

•	Marker Lamps Inoperative

•	Marker Lamps Inoperative - Output at Trailer/Upfitter Connector

•	Park, License, and Tail Lamps Inoperative

•	Park Lamps Inoperative - Output at Trailer/Upfitter Connector

•	Stop Lamps Always On

•	Stop Lamps Inoperative

•	Stop Lamps Inoperative - Output at Trailer/Upfitter Connector

•	Turn Signal Lamps and/or Indicators Inoperative

•	Turn Signal Lamps Inoperative - Output at Trailer/Upfitter Connector