TM 9-2320-289-20
Table 2-4. Electrical Troubleshooting (Con’t)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 9.
Hold run-start switch in “START” position or on-off switch in “ON” position. Check
voltage between terminal “D“ of heater wiring harness connector and ground.
Voltage should be 24.0.
If voltage is correct, perform step 10.
If voltage is not correct, replace heater control box. (See paragraph 10-35,
11-3, or 11-20)
Step 10. Hold run-start switch in “START” position or on-off switch in “ON” position. Check
voltage between terminal “B“ of heater wiring harness connector and ground.
Voltage should be 24.0.
If voltage is correct, replace heater. (See paragraph 10-36, 11-8, 11-16, or
11-21)
If voltage is not correct, replace heater control box, (See paragraph 10-35,
11-3, or 11-20)
HORN
23. INOPERATIVE
Step 1.
Check 15 amp horn fuse. (See paragraph 4-12)
Replace if burned out.
Step 2.
Disconnect lead from horn. Check for voltage while pressing horn button,
If there is voltage, check security and condition of horn ground. If ground is
good, replace horn. (See paragraph 4-22)
If there is no voltage, perform step 3.
Step 3.
Remove horn relay. (See paragraph 4-22) Turn key to “RUN” position. Using
jumper wire, connect lead terminals. Depress horn button.
If horn sounds, replace relay.
If horn does not sound, trace circuit back to fuse box. (See wiring diagram
F-20 or F-21)
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