ALL MARKER LIGHTS DO NOT OPERATE (S/N YB6122 075 AND UP). -725550316

TM 9-2330-385-14

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

20. ALL MARKER LIGHTS 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)

Multimeter (Item 28, Appendix J)

Equipment Condition

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

Personnel Required

24 vdc cable connected to truck, (Para 2-9)

Two

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

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

NOTE

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

START

TEST OPTIONS

KNOWN INFO

WARNING

Read WARNING

Truck electrical system OK.

Voltage test.

on Page 4-118.57

24 vdc cable OK.

REASON FOR QUESTION

POSSIBLE PROBLEMS

If 22 to 28 vdc are not present at

Are 22 to 28 vdc measured

diode assembly connector

Wire 1008C faulty.

on wire 1008C-6 at diode

terminal 10, all marker lights will

Wire 1012B faulty.

assembly connector,

not operate.

Diode assembly faulty.

terminal 10?

Repair wire 1008C-6

(see schematic, Fig

FO-1.1) or replace

trailer main wire

harness (Para 4-30.1).

Verify repair,

go to Step 3 of this

Fault.

YES

4-118.56