TM 9-2320-260-10
Table 3-1. Troubleshooting (Cont'd)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
51. ENGINE COOLANT HEATER FAILS TO START WHEN RUN-OFF-START SWITCH IS HELD
IN START POSITION.
WARNING
Exhaust gases can kill. Do not operate engine coolant heater in closed area
occupied by personnel.
CAUTION
Do not operate the engine coolant heater and personnel heater at the same time.
NOTE
Heater will not operate if RUN-OFF-START switch is moved to RUN position
before indicator lamp lights up.
Step 1.
Check to see if battery switch is in OFF position.
Turn battery switch to ON position.
Step 2.
Check fuel level on fuel gage.
Fill fuel tank(s) if necessary.
Step 3.
Check to see if heater fuel shutoff valve, located in battery box, and electric fuel pump
shutoff valve, located near air cleaner assembly, are closed. (Refer to paragraph 2-43d.)
Open both fuel shutoff valves.
Step 4.
Depress PRESS-TO-TEST button on heater control box to check operation of circuit.
If indicator lamp does not light up, notify organizational maintenance.
Step 5.
Check to see if HI-LO switch on heater control box is set to HI or LO position.
Set HI-LO switch to HI or LO position.
NOTE
Select HI position if engine is cold. Select LO position if engine is already well
heated. Switch will automatically change to LO position when coolant temperature
exceeds 195°F (90°C). Switch will automatically change to HI position when
coolant temperature drops below 120°F (48°C).
52. EXCESSIVE ELAPSED TIME BEFORE HEATER IGNITION.
Check battery indicator gage.
If needle is not in green area, perform malfunction 1, step 2. If this does not correct
problem, notify organizational maintenance.
53. HEATER FAILS TO CONTINUE BURNING.
Check fuel level on fuel gage.
Fill fuel tank(s) if necessary.
54. HEATER OUTPUT IS LOW.
Check if HI-LO switch is in LO position.
Set switch to HI position.
55. WINDSHIELD DEFROSTERS NOT OPERATING.
Step 1.
Check adjustment of defroster control handle.
Adjust defroster control handle.
Step 2.
Check for restrictions in defroster deflectors.
Clear restriction.
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