4-14. 12-VOLT ELECTRICAL SYSTEM TROUBLESHOOTING PROCEDURES (CONT).
11. FRONT SIDE MARKER LIGHT(S) DO NOT OPERATE
(S/N YB6122 075 AND UP).
Tools and Special Tools
Tool Kit, General Mechanic's: Automotive
(Item 50, Appendix J)
Multimeter (Item 28, Appendix J)
Engine OFF, (TM 9-2320-364-10)
Wheels chocked, (TM 9-2320-364-10)
12 vdc cable assembly connected to
truck, (Para 2-9)
Parking brake applied (TM 9-2320-364-10)
The following troubleshooting procedures cover the left front side marker light, but they apply to all front side marker
All electrical wires and components listed in this troubleshooting procedure are illustrated and located in FO-1.1.
Truck electrical system OK.
on Page 4-202.3
All other trailer lights operate.
REASON FOR QUESTION
Are 10 to 14 vdc measured on
If voltage is not supplied to
marker light, marker light will
wire 1012B at front side
Wire 1012B faulty.
marker light ?
Marker light faulty.
Wire 1435 faulty.
Repair wire 1012B
(see schematic, Fig
FO-3) or replace
trailer main wire
(Para 4-30.1). Verify
repair, go to Step 3 of