ALL MARKER LIGHTS DO NOT OPERATE (S/N YB6122 075 AND UP). -725550482

TM 9-2330-385-14

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

19. 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 9-3220-364-10

(Item 50, Appendix J)

Multimeter (Item 28, Appendix J)

Equipment Condition

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

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

Personnel Required

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

Two

12 vdc cable assembly connected to truck,

(Para 2-9)

NOTE

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.

Voltage test.

on Page 4-202.57

All other trailer lights operate.

REASON FOR QUESTION

POSSIBLE PROBLEMS

If voltage is not present between

Are 10 to 14 vdc measured

terminals B and A on 12 vdc cable

12 vdc cable faulty.

between terminals B and A

assembly, rear side marker light

Wire 1012-2 faulty.

on trailer end of 12 vdc

and rear marker lights will not

Diode assembly faulty.

cable?

operate.

Wire 1012B faulty.

Repair (Para 4-31) or

replace (Para 2-9) 12

vdc cable. Verify

repair, go to Step 3 of

this Fault.

YES

4-202.56