REAR MARKER LIGHT(S) DO NOT OPERATE (S/N YB6122 075 AND UP). -725550440

TM 9-2330-385-14

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

13. 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)

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

Personnel Required

12 vdc cable assembly connected to truck,

Two

(Para 2-9)

Parking brake applied, (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

KNOWN INFO

TEST OPTIONS

Truck electrical system OK.

Does at least one rear or rear

Visual inspection.

All other trailer lights operate.

side marker light operate when

power is applied?

REASON FOR QUESTION

POSSIBLE PROBLEMS

If no rear or rear side marker

Wire 1012B faulty.

lights operate, fault is in trailer

Wire 1435 faulty.

main wire harness 1012B. If at

Marker light faulty.

least one rear or rear side mark-

er light operates, fault is in rear

junction box through rear mark-

er 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

4-202.14