BLACKOUT STOPLIGHT(S) DO NOT OPERATE. (Cont) -725550232

TM 9-2330-385-14

7. BLACKOUT STOPLIGHT(S) DO NOT OPERATE (CONT).

KNOWN INFO

WARNING

TEST OPTIONS

Read WARNING

Truck electrical system OK.

on Page 4-91

Voltage test.

All other trailer lights operate.

Taillights operate indicating

LED composite light ground

REASON FOR QUESTION

Are 22 to 28 vdc measured on

is OK

wire 1678/23-28 at blackout

Blackout stoplight lamp OK.

If 22 to 28 vdc are not present

Blackout stoplight OK.

on wire 1678/23-28, blackout

taillight connector?

24 vdc cable OK.

stoplight will not operate.

Connector MC15 OK.

Front junction box OK.

Wire 1678C-18 OK.

Rear junction box OK.

Repair wire

LED composite light OK.

1678/23-28 (see

Ground wire 1435 OK.

schematic, Fig FO-1)

or replace composite

POSSIBLE PROBLEMS

light harness

(Para 4-30).

Wire 1678/23-28 faulty.

Verify repair, go to

Step 10 of this Fault.

YES

If composite lights

are installed, fault not

corrected. Notify

supervisor.

Replace LED composite

light (para 4-29). Verify

repair, go to Step 10 of

this Fault.

4-90