BLACKOUT TAILLIGHT(S) DO NOT OPERATE (S/N YB6122 075 AND UP). (Cont) -725550302

TM 9-2330-385-14

17. BLACKOUT TAILLIGHT(S) DO NOT OPERATE (S/N YB6122 075 AND UP) (CONT).

KNOWN INFO

TEST OPTIONS

WARNING

Read WARNING

Truck electrical system OK.

Voltage test.

on Page 4-118.43

All other trailer lights operate.

Taillights operate indicating

REASON FOR QUESTION

LED composite light ground

(wire 1435) OK.

If 22 to 28 vdc are present on

Are 22 to 28 vdc measured on

24 vdc cable OK.

wire 1680C/24 LED composite

wire 1680C/24 at LED com-

Wire 1680C OK.

light is faulty. If not, composite

posite light?

light wire harness 1680C is

faulty.

POSSIBLE PROBLEMS

LED composite light faulty.

Wire 1680C/24 faulty.

Repair wire 1680C

(see schematic, Fig

FO-1.1) or replace

composite light wire-

harness (Para

4-30.1). Verify repair,

go to Step 7 of this

Fault.

YES

Replace LED

composite light

(para 2-49). Verify

repair, go to Step 4

of this Fault.

4-118.42