Testing

1. Unplug the horn wire harness connector. Measure the resistance between the ground circuit cavity of the horn wire harness connector and a good ground. There should be zero ohms resistance. If OK, go to Step 2. If not OK, repair the faulty horn ground circuit as required.
2. With the horn wire harness connector still unplugged, depress the horn switch. There should be battery voltage at the horn relay output circuit cavity of the horn wire harness connector. If OK, replace the faulty horn. If not OK, repair the open circuit to the horn relay as required.