TAILLIGHTS AND STOPLIGHTS DO NOT OPERATE (S/N YB6122 075 AND UP).

TM 9-2330-385-14

4-14. 12-VOLT ELECTRICAL SYSTEM TROUBLESHOOTING PROCEDURES (CONT).

17. TAILLIGHTS AND STOPLIGHTS DO NOT OPERATE (S/N YB6122 075 AND UP).

INITIAL SETUP

Tools and Special Tools

References

Tool Kit, General Mechanic's: Automotive

TM 9-2320-364-10

(Item 50, Appendix J)

Equipment Condition

Multimeter (Item 28, Appendix J)

Engine OFF, (TM 9-2320-364-10)

12 vdc cable assembly connected to truck,

Personnel Required

(Para 2-9)

Two

Parking brake applied, (TM 9-2320-364-10)

Wheels chocked, (TM 9-2320-364-10)

NOTE

The following troubleshooting procedures cover the left taillight and stoplight, but they apply to right side taillight and

stoplight also.

All electrical wires and components listed in this troubleshooting procedure are illustrated and located in FO-1.1.

START

KNOWN INFO

TEST OPTIONS

WARNING

Read WARNING

Truck electrical system OK.

Continuity test.

on Page 4-202.49

All other trailer lights operate.

REASON FOR QUESTION

POSSIBLE PROBLEMS

Is continuity measured be-

If continuity is not measured

tween wire 1435 at LED

Wire 1435 faulty.

between wire 1435 wire and a

composite light and a known

LED composite light faulty.

known good ground, LED

good ground?

composite light ground (wire

1435) is faulty. If continuity is

measured, LED composite light

is faulty and lights will not

operate.

Repair wire 1435

(see schematic, Fig

FO-1.1) or replace rear

side marker light

harness (Para 4-30).

Verify repair, go to

Step 2 of this Fault.

YES

Replace LED

composite light

(Para 4-29).

Verify repair, go to

Step 2 of this

Fault.

4-202.48