Horn Relay Circuit Test
NOTE:
Electrical connectors must remain connected during horn relay testing.
- Locate yellow wire ("E" models) or Yellow/Light Blue dot wire (Bronco and "F" models) at connector "X". Check for battery voltage on pin side of connector. See Fig. 2.
- Locate Blue/Yellow stripe wire ("E" models) or Dark Blue wire (Bronco and "F" models) at connector "Y". Check for battery voltage on socket side of connector. With voltmeter still connected to socket, depress horn switch.
- Horn should sound, but voltmeter should indicate "zero" volts. If voltmeter still indicates battery voltage when horn switch is depressed, check horn switch or steering column wiring for an open circuit.
- To by-pass horn switch and check horn relay, momentarily ground Blue/Yellow stripe wire ("E" models) or Dark Blue wire (Bronco and "F" models) on socket side of connector "Y".
- If horn still does not sound, check Yellow-/Green stripe wire ("E" models) or Yellow/Light green wire (Bronco and "F" models) at connector "X" for battery voltage while relay is activated. If battery voltage is present when relay is activated, an open circuit is present between connector "X" and horn.
- If battery voltage is present in step 1) and horn relay failed to operate in step 3), replace relay.