SERVICE BLACKOUT (INFRARED) HEADLAMP CIRCUIT (LEAD 515). (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 2 ohms, 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.

Step 2.

To access line disconnect, remove hull transmission compartment deck

assembly. Refer to page 2-938. Disconnect lead 515. Place red probe in

lead 515. Ground black probe. Press headlamp dimmer switch for low

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 515 from line disconnect to headlamp

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

vehicular light switch OFF.

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