4-13. 24-VOLT ELECTRICAL SYSTEM TROUBLESHOOTING (CONT).
20. ALL MARKER LIGHTS 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)
24 vdc cable connected to truck, (Para 2-9)
Parking brake applied, (TM 9-2320-364-10)
Wheels chocked, (TM 9-2320-364-10)
All electrical wires and components listed in this troubleshooting procedure are illustrated and located in FO-1.1.
Truck electrical system OK.
24 vdc cable OK.
REASON FOR QUESTION
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.
Diode assembly faulty.
Repair wire 1008C-6
(see schematic, Fig
FO-1.1) or replace
trailer main wire
harness (Para 4-30.1).
go to Step 3 of this