BLACKOUT TAILLIGHT(S) DO NOT OPERATE.

TM 9-2330-385-14

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

6. BLACKOUT TAILLIGHT(S) DO NOT OPERATE.

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)

Materials/Parts

24 vdc cable assembly connected to truck,

Locknut (Item 31, Appendix I)

(Para 2-9)

Packing, Preformed (Item 59, Appendix I)

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

Personnel Required

Two

NOTE

The following troubleshooting procedures cover the left blackout taillight, but they apply to both blackout taillights.

All electrical wires and components listed in this troubleshooting procedure are illustrated and located in FO-1.

Trailer may be equipped with composite lights or LED composite lights.

START

KNOWN INFO

TEST OPTIONS

Truck electrical system OK.

Visual inspection.

Does at least one blackout

All other trailer lights operate.

taillight operate when power

Taillights operate indicating

REASON FOR QUESTION

is applied?

LED composite light ground

is OK.

If no blackout taillights operate,

fault is in 24 vdc cable through

POSSIBLE PROBLEMS

wire 1680C-19. If at least one

blackout taillight operates, fault

is in rear junction box through

Blackout taillight faulty.

faulty lamp.

Blackout taillight lamp faulty.

Wire 1680/24-27 faulty.

24 vdc cable faulty.

Connector MC15 faulty.

Front junction box faulty.

Wire 1680C-19 faulty.

Go to Step 6 of this

Rear junction box faulty.

Fault.

YES

If composite lights

are installed, go to

Step 2 of this Fault.

If LED composite

lights are insalled,

go to Step 5 of this

Fault.

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