Roof Beacon Lamp Inoperative

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Step	Action	Yes	No
Schematic Reference: Upfitter Provision Schematics in Wiring Systems Connector End View Reference: Lighting Systems Connector End Views
1	Did you perform the Lighting Systems Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Lighting Systems
2	Verify that the roof beacon lamp is inoperative. Does the roof beacon lamp operate normally?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Place the roof beacon switch in the ON position. Connect a test lamp between the power and ground circuits of the roof beacon lamp connector. Does the test lamp illuminate?	Go to Step 8	Go to Step 4
4	Test the ground circuit of the roof beacon lamp for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 5
5	Remove the roof beacon switch. Place a fused jumper between the hazard switch signal and battery positive voltage circuits of the roof beacon switch connector terminals. Does the roof beacon lamp illuminate?	Go to Step 9	Go to Step 6
6	Test the following circuits for a high resistance, open or a short to ground: Battery positive voltage circuit of the switch Battery positive voltage circuit of the relay Hazard switch signal circuit of the relay Hazard flasher signal circuit of the relay Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 7
7	Test the ground circuit of the roof beacon relay for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 10
8	Replace the bulb or lamp assembly. Refer to upfitter instructions. Did you complete the replacement?	Go to Step 11	-
9	Replace the roof beacon switch. Did you complete the replacement?	Go to Step 11	-
10	Replace the roof beacon relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement?	Go to Step 11	-
11	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 3