HEATING SYSTEMS TROUBLESHOOTING

TM 9-2320-361-24-1

0015 00

FIELD TROUBLESHOOTING

2-1/2 TON, 6X6, M44A2 SERIES TRUCKS (MULTIFUEL)

HEATING SYSTEMS TROUBLESHOOTING

Table 1. Heating Systems Troubleshooting Procedures.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Test 1. Test engine manifold heater

1. ENGINE MANIFOLD

ignition circuit for battery

HEATER DOES NOT

voltage.

WORK

1. Disconnect lead 55 from

engine manifold heater

ignition unit. Manifold heater

fuel pump is now disabled.

2. Set multimeter to a voltage

range that will measure 24 VDC.

3. Turn power accessory switch

to ON position.

4. Push manifold heater switch

and hold.

5. Touch positive lead of

1. If battery voltage is present, go to

multimeter to contact end of

test 4.

lead 55 and negative lead to

2. If battery voltage is not present, go

frame ground.

to test 2.

PIN B

PIN A

FUEL PUMP

IGNITION COIL

LEAD 55

MANIFOLD HEATER

FUEL PUMP HARNESS

TEST 1

STEP 5

0015 00-1