TM 5-3805-254-20-1
ORGANIZATIONAL TROUBLESHOOTING - CONTINUED
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
22. ONE BACKUP LIGHT DOES NOTWORK.
WARNING
Although KEY SWITCH must be on and battery ground cable connected to test electrical circuit
voltage, turn off KEY SWITCH and disconnect battery ground cable before doing resistance tests
or replacing parts. This will keep you from getting shocked and prevent damage to parts and
equipment.
NOTE
Scrape painted surfaces to bare metal before connecting test leads to ensure correct multimeter
readings.
Steps 1 and 2 are typical for both backup light sockets.
Step 1. Using number one cross-tip screwdriver, unscrew and take out four screws (1) and lens (2). Push
backup lamp (3) in and turn counterclockwise and take out. Set multimeter to ohms scale and adjust
to 0 ohms. Connect red test lead to contact (4) and black test lead to metal base (5). Check for 0
ohms on multimeter. ¾> Disconnect test leads.
a. If multimeter does not read 0 ohms, replace backup lamp (3). Put backup lamp (3) into socket
(6), aligning pins with slots. Push in, turn clockwise, and release. Put lens (2) into
stoplight/taillight assembly (7). Screw in four screws (1) and tighten using number one cross-
tip screwdriver.
b. If multimeter reads 0 ohms, go to step 2.
Step 2. Check socket (6) for corrosion or rusted out condition.
a. If socket (6) is corroded, clean using emery cloth. Put backup lamp (3) into socket (6), aligning
pins with slots. Push in, turn clockwise and release. Put lens (2) into stoplight/taillight
assembly (7). Screw in four screws (1) and tighten using number one cross-tip screwdriver.
Go to step 3.
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