BACK-UP ALARM DOES NOT SOUND

TM 10-3930-638-24&P

2-23. HORN AND BACK-UP ALARM SYSTEM TROUBLESHOOTING (cont)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

2. BACK-UP ALARM DOES NOT SOUND

Step 1. Turn IGNITION switch key to ON position and

temporarily connect a jumper wire to terminals of

back-up alarm switch.

a. If back-up alarm sounds, replace back-up

b. If back-up alarm does not sound, proceed

to step 2.

Step 2. Disconnect wire from positive terminals of back-up

alarm.

Temporarily connect a jumper wire between positive

battery cable and positive terminal of back-up

alarm.

a. If back-up alarm sounds, reconnect wire to

positive alarm terminal and proceed to step 3.

b. If back-up alarm does not sound, connect a

jumper wire to vehicle ground and back-up

alarm negative terminal. If alarm does not

sound with ground jumper at negative

terminal and battery positive jumper at

positive terminal, replace back-up alarm

Step 3. Turn and hold IGNITION switch key at LAMP TEST position.

a. If at least one warning indicator (TRANSMISSION TEMPERATURE, HYDRAULIC

FILTER, or ENGINE TEMPERATURE) is on, check for open circuit in wiring between

back-up alarm, back-up alarm switch, and 6 ampere circuit breaker.

b. If at least one warning indicator is not on, turn IGNITION switch key to ON position and

check if a slight buzz can be heard at electric fuel pump. If slight buzz indicating electric fuel

pump operation is not heard, troubleshoot IGNITION switch (para 2-25). If slight buzz is heard,

troubleshoot warning indicators (para 2-25).

NOTE

If flood lights, tail lights, stop lights and gage lights are all inoperative, turn

IGNITION switch key to OFF position. Connect positive voltmeter lead to

terminal F of VEHICLE LIGHTS switch cable connector and negative

voltmeter lead to vehicle ground. If voltmeter does not indicate 24 Vdc with

IGNITION switch key set at ON position, check for open circuit in wiring

between terminal F of cable connector and IGNITION switch. If wiring

check is satisfactory, replace IGNITION switch (para 2-28c).