SERVICE BLACKOUT (INFRARED) HEADLAMP CIRCUIT (LEAD 514). (Cont)

TM 9-2350-238-20-1

2-12. ELECTRICAL CIRCUIT TROUBLESHOOTING (CONT).

Step 1.

Set MASTER switch OFF. Remove inoperative lamp from service

headlamp. Refer to page 2-601. Connect multimeter to the parallel lamp

terminals. If multimeter indicates about 1 ohm, go to step 2. If multimeter

indicates infinity, replace lamp. Refer to page 2-601.

Make sure MASTER switch is OFF before repairing electrical

circuits. Failure to observe this warning could result in injury to

personnel.

To access line disconnect, remove hull transmission compartment deck

Step 2.

assembly. Refer to page 2-938. Disconnect lead 514. Place red probe in

lead 514. Ground black probe. Press headlamp dimmer switch for high

beam operation. Set MASTER switch ON. Turn vehicular light switch to

BO DRIVE. Set BO-IR switch to IR. If multimeter indicates about 24 volts,

repair service headlamp assembly. Refer to page 2-601. If multimeter

indicates no voltage, repair lead 514 from line disconnect to headlamp

dimmer switch. Refer to page 2-371. Set MASTER switch OFF. Turn ve-

hicular light switch OFF. Connect lead.

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