Test Description
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
4. Tests if ground is constantly being applied to the horn relay.
5. The horn relay control circuit includes the horn switch. The horn switch must be tested for a short to ground when testing the relay control circuit.