TM 9-2320-260-20
Table 2-4. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
22. BLACKOUT STOPLIGHT LAMP DOES NOT LIGHT
Test 1. Test for battery voltage at rear composite light.
Step 1. Turn main light switch to OFF position.
Step 2. Disconnect lead 23 at rear composite light on side of vehicle where blackout stoplight
has failed.
Step 3. Turn main light switch to BLACKOUT MARKER or BLACKOUT DRIVE position.
Step 5. Depress brake pedal and check for battery voltage on contact end of lead 23.
a. If battery voltage is present, go to test 2.
b. If battery voltage is not present, go to malfunction 15, test 3 and check front wiring
harness pin N.
Test 2. Test continuity of filament in blackout stoplight lamp.
Step 1. Set multimeter to RX1 scale.
Step 2. Check continuity between lead 23 attached to rear composite light and frame ground
pin N.
a. Replace blackout taillight lamp if continuity is not present (para. 4-46).
b. If continuity is present, check for corroded contacts at lamp and on lead 23 connection
to rear wiring harness. Connect lead 23.
END OF TESTING!
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