Diagnostic Aids
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Perform a visual inspection for loose or poor connections at all related components. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems.