"On" Circuit Test

Turn ignition "ON" and connect a voltmeter to light blue/black hash wire at amplifier six-way connector. Voltmeter should read 12 volts when "ON" switch in steering wheel is depressed and held. If no voltage is available, conduct Horn Relay Circuit Test and Control Switch Test. Release the "ON" button. A 12 volt reading should remain on voltmeter indicating the "ON" circuit is engaged. If voltage does not remain, check for ground at amplifier, fuse and/or circuit breaker. Insert a known good amplifier and recheck "ON" circuit if necessary.