TM-9-2320-361-20

2-1/2-TON, 6x6, M44A2 SERIES TRUCKS (MULTIFUEL)

TECHNICAL MANUAL; UNIT MAINTENANCE

OCTOBER 1991

TM-9-2320-361-20 - Page 186 of 1207

TM 9-2320-361-20

Table 2-4. Electrical Troubleshooting (Contd).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

LIGHTING SYSTEM

17.

HEADLIGHT DOES NOT OPERATE ON LOW OR HIGH BEAM, OR BOTH HEADLIGHTS INOPERATIVE

Test 1. Test headlamp connection voltage.

Step 1. Check for loose connections at headlamp and wiring harness and for broken headlamp.

Step 2. Turn main light switch to OFF position.

Step 3. Disconnect leads 17 (high beam), 18 (low beam), and 91 (ground) behind headlamp.

Step 4. Turn main light switch lever to SERVICE DRIVE position.

Step 5. Check low beam and high beam voltage.

a. Push dimmer switch to LOW position. Check for battery voltage between lead 18 and

lead 91.

b. If voltage is present, go to step 6. If voltage is not present, go to test 2.

c. Push dimmer switch to HIGH position. Check for battery voltage between lead 17 and

lead 91.

d. If voltage is present, go to step 6.

Step 6. Check continuity of LOW-beam filament.

a. Place multimeter leads between headlamp connectors 18 and 91 at rear of headlamp.

b. If continuity is not present, replace sealed beam headlamp (para. 4-39).

Step 7. Check continuity of HIGH-beam filament.

a. Place multimeter leads between headlamp connectors 17 and 91 at rear of headlamp.

b. If continuity is not present, replace sealed beam headlamp (para. 4-39).

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