Amplifier Test: Notes

CAUTION: DO NOT use a test light to perform amplifier tests, as excessive current draw will damage electronic components. Use only a voltmeter of 5000 ohm/volt rating or higher.

Turn ignition on, and connect a voltmeter between ground and Lt. Blue/Black wire at amplifier 6-way connector. Voltmeter should read 12 volts when "ON" switch in steering wheel is depressed and held. If no voltage is present, see HORN RELAY TEST and CONTROL SWITCH TEST.
Release "ON" button. A 7.8 volt reading should remain on voltmeter, indicating "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.