TM 5-3805-254-20-1
ORGANIZATIONAL TROUBLESHOOTING - CONTINUED
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
21. BOTH BACKUP LIGHTS DO NOT WORK - CONTINUED.
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.
Step 11.
Pull wire connector (1) off backup light switch (2) and position locator hole (3) at 12 o’clock. Set
multimeter to 20 vdc scale. Connect red test lead to wire connector terminal (4) and black test lead to
ground. Have assistant rotate KEY SWITCH (5) clockwise to on position. Check for 11 to 13 vdc on
multimeter. Have assistant rotate KEY SWITCH (5) counterclockwise to off position. Disconnect test
leads.
a.
If multimeter does not read 11 to 13 vdc, go to step 12.
b.
If multimeter reads 11 to 13 vdc, go to step 13.
Step 12.
Test wire connector (1) as follows: Disconnect batteries (page 2-424). Set multimeter to ohms scale and
adjust to 0 ohms. Position locator hole (3) at 12 o’clock. With assistant, connect red test lead to wire
connector terminal (4) and black test lead to terminal (6) on junctional box (7). Check for 0 ohms on
multimeter. Disconnect test leads.
If multimeter reads no continuity, wire connector (1) must be replaced. Notify Direct
Support Maintenance.
2-152
