Table 1. Electric Horn Circuits Troubleshooting Procedures.

TM 9-2320-303-24-1

Table 1. Electric Horn Circuits Troubleshooting Procedures.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Electric Horn Does Not Operate.

1. Check horn 15A fuse.

If defective, replace 15A fuse (WP

2. Check for +12 VDC at lead If +12 VDC is present, go to step

420JD from auxiliary light 3. If no voltage is present, repair

power bus.

lead 420JD.

3. Disconnect horn relay from If +12 VDC is present, go to step

connector. Check for +12 VDC 4. If no voltage is present, repair

at connector 30.

lead 24.

4. Disconnect horn relay. Check If +12 VDC is present, go to step

for +12 VDC at connector 85. 5. If no voltage is present, repair

lead 24.

5. Disconnect lead 25 from horn If +12 VDC is present, go to step

button. Check for +12 VDC at 6. If no voltage is present, replace

lead 25.

6. Disconnect ground lead from If continuity is indicated, go to

horn button. Check for step 7. If no continuity is

continuity between ground lead indicated, repair ground lead.

and ground.

7. Disconnect lead 25 from horn

If continuity is indicated, go to

button. Press horn switch.

step 8. If no continuity is

Check for continuity between

indicated, replace horn button

switch contacts.

8. Disconnect lead 26 from horn. If +12 VDC is present, go to step

Check for +12 VDC at lead 26 9. If no voltage is present,

with horn button pressed.

disconnect horn relay and check

for continuity between connector

87 and lead 26. If continuity is

indicated, replace horn relay (WP

indicated, repair lead 26.