Horn Relay Circuit Test

NOTE: Electrical connectors must remain connected during horn relay testing.

Measure voltage between circuit No. 460 (Yellow/Light Blue wire) and ground at relay. Voltage should be 12 volts. If voltage is not present, check fuse No. 8 on Bronco II and Ranger or fuse No. 16 on Aerostar, Bronco, and "E" and "F" Series.
On Aerostar, Bronco II and Ranger, if voltage was present in step 1), depress horn button. Voltage should drop to zero and horn should sound. If horn does not sound and voltage stays the same, check for 12 volts at circuit No. 6 (Yellow/Light Green wire) at horn relay. If voltage is not present, replace relay and retest.
If 12 volts are present, jumper circuit No. 6 to ground. If horn sounds, replace horn pad. If horn does not sound, check for 12 volts at circuit No. 1 (Dark Blue wire) at terminal No. 3 with terminal No. 2 grounded. If voltage is not present, replace relay and retest. If voltage is present, check all horn connections.
On Bronco and "E" and "F" Series, if voltage was present in step 1), check for 12 volts on circuit No. 6 (Yellow/Light Green wire) on "E" Series and on circuit No. 1 (Dark Blue wire) on Bronco and "F" Series.
If voltage is present, depress horn button. Voltage should drop to zero and horn should sound. If horn does not sound and voltage remains at 12 volts, ground circuit No. 1 (Dark Blue wire) on Bronco and "F" Series to body ground. Ground circuit No. 6 (Yellow/Light Green wire) on "E" Series to body ground.
If horn still does not sound, check for 12 volts on circuit No. 1 on Bronco and "F" Series or on circuit No. 6 on "E" Series when relay activates. If 12 volts are present, repair open between horn and horn relay. If voltage is not present, replace relay.