HORN AND BACK-UP ALARM SYSTEM TROUBLESHOOTING

TM 10-3930-638-24&P

2-23. HORN AND BACK-UP ALARM SYSTEM TROUBLESHOOTING

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. HORN DOES NOT SOUND

Disconnect positive wire from side of horn.

Step 1.

Connect positive voltmeter lead to connector on

positive wire, and negative voltmeter lead to

vehicle ground.

a. If voltmeter indicates 24 Vdc, reconnect

positive wire to side of horn and proceed to

step 2.

b. If voltmeter does not indicate 24 Vdc,

troubleshoot 25 ampere circuit breaker

(para 2-21, malfunction entry 2, step 6).

If 25 ampere circuit breaker test is

satisfactory, check for open circuit in

wiring between battery positive post and

connector on horn positive wire.

Step 2. Disconnect horn button wire from bottom of horn.

Temporarily connect jumper wire from terminal on bottom of horn to vehicle ground.

a. If horn sounds, reconnect horn button wire to bottom of horn and proceed to step 3.

b. If horn does not sound, replace horn (para 2-32a).

Disconnect horn button wire

Step 3.

from terminal on steering

column. Temporarily connect

jumper wire from connector on

horn button wire to vehicle

ground.

a. If horn does not sound,

check for open circuit in

wire between steering

column and horn.

b. If horn sounds, replace