TM 9-2320-289-20
Table 2-4. Electrical Troubleshooting (Con’t)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 2.
Step 3.
Step 4.
Step 5.
Step 6.
Step 7.
Step 8.
NOTE
Step 2 applies to M1010 personnel heater only.
Remove access cover from ambulance body fuse panel. (See paragraph 4-13)
Check 30 amp heater fuses.
Replace fuse if burned out.
If fuse is good, perform step 3.
Ensure that truck fuel tank is at least ¼ full. Add fuel if low.
Hold run-start switch in “START” position.
If heater fuel pump runs, perform step 5.
If heater fuel pump does not run, trace circuit. (See wiring diagram F-22 or
F-28)
Bleed heater. (See paragraph 10-36, 11-7, 11-14, or 11-21)
Set run-start switch to “OFF” position.
Remove side panel from heater
compartment (ambulance heater only). Disconnect wiring harness from heater and
heater control box. Check continuity through all wiring harness terminals.
If there is continuity, perform step 7.
If there is no continuity, repair if possible or replace. (See paragraph 10-35,
11-10, 11-17, or 11-23)
Connect wiring harness to heater. Check voltage between terminal “D“ of heater
control box connector and ground. Voltage should be 24.0.
If voltage is correct, perform step 8.
If voltage is not correct, check voltage at gray lead into heater control box
(ambulance heater) or red lead into heater control box (all except ambulance
heater). If there is still no voltage, trace circuit. (See wiring diagram F-22,
F-29, or F-30) If there is voltage,
replace heater control box. (See
paragraph 10-35, 11-3, or 11-20)
Hold run-start switch in “START” position or on-off switch in “ON” position. Check
voltage between terminal “C” of heater control box connector and ground. Voltage
should be 24.0.
If voltage is correct, perform step 9.
If voltage is not correct, replace heater control box. (See paragraph 10-35,
11-3, or 11-20)
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