REAR MARKER LIGHT(S) DO NOT OPERATE (S/N YB6122 075 AND UP). -725550274

TM 9-2330-385-14

4-13. 24 VOLT ELECTRICAL SYSTEM TROUBLESHOOTING PROCEDURES (CONT).

14. REAR MARKER LIGHT(S) 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)

24 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 one rear marker light, but they apply to all rear marker lights.

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

START

TEST OPTIONS

KNOWN INFO

Visual inspection.

Truck electrical system OK.

Does at least one rear or rear

All other lights on trailer

side marker light operate?

operate.

REASON FOR QUESTION

POSSIBLE PROBLEMS

If no rear or rear side marker

lights operate, fault is in trailer

Wire 1012B faulty.

main wire harness wire 1012B.

Wire 1435 faulty.

If at least one rear or rear side

Rear marker light faulty.

marker light operates, fault is in

rear junction box through rear

marker light.

Repair wire 1012B

(see schematic, Fig

FO-1.1) or replace

trailer main wire

harness (Para

4-30.1). Verify repair,

go to Step 4 of this

Fault.

YES

4-118.14