Table 1. Indicator, Gauges, and Warning System Troubleshooting - continued

TM 9-2320-361-24-1

0014 00

INDICATORS, GAUGES, AND WARNING SYSTEM TROUBLESHOOTING (Contd)

Table 1. Indicator, Gauges, and Warning System Troubleshooting (Contd).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

NOTE

10. HORN DOES NOT

OPERATE

Troubleshooting of the electrical horn

and air horn are the same.

Test 1. Test input voltage to horn

circuit breaker.

1. Turn main light switch to

SERVICE DRIVE position.

2. Remove lead 25 from circuit

horn breaker.

3. Set multimeter to a voltage

range that will measure

24 VDC.

4. Connect negative lead to

frame ground.

1. If voltage is not present, replace

5. Touch positive lead to horn

horn circuit breaker.

circuit breaker contact.

2. If voltage is present, go to test 2.

Test 2. Test air horn solenoid.

1. Remove lead 25 from pin B of

air horn solenoid.

2. Connect negative lead of

multimeter to frame ground.

1. If voltage is present, go to test 3.

3. Touch positive lead to pin B of

solenoid.

2. If voltage is not present, go to

step 4.

1. If voltage is present, replace air

4. Remove lead 25 connected to

horn solenoid (WP 0114 00).

pin A of air horn solenoid.

Connect negative lead to

2. If voltage is not present, repair or

frame ground. Touch positive

replace lead 25.

lead to contact end of lead 25.

Test 3. Test horn switch input

voltage.

1. Remove horn button

(WP 0113 00) until lead 25

can be seen.

2. Set multimeter to a voltage

range that will measure 24 VDC.

3. Connect negative lead to

frame ground.

1. If voltage is not present, repair or

4. Touch positive lead to lead 25

replace lead 25 (WP 0090 00).

contact end.

2. If voltage is present, go to test 4.

0014 00-18