TM-9-2320-366-20-1

M1083 SERIES, 5 TON, 6x6, MEDIUM TACTICAL VEHICLES (MTV)

TECHNICAL MANUAL; MAINTENANCE INSTRUCTIONS; UNIT MAINTENANCE; VOLUME NO. 1 OF 5

FEBRUARY 2006

CHANGE 3

TM-9-2320-366-20-1 - Page 1258 of 1824

e55. BACKUP LIGHT DOES NOT ILLUMINATE (CONT)

TM 9-2320-366-20-1

2-704

Change 1

TEST OPTIONS

REASON FOR QUESTION

KNOWN INFO

18.

POSSIBLE PROBLEMS

Do backup lights operate

with new WTEC III relay

K25 installed?

WTEC III Relay K25

Replacement Test

If backup lights operate

with new WTEC III relay

K25 installed, WTEC III

relay K25 is faulty.

If

backup lights do not

operate with new WTEC III

relay K25 installed,

WTEC III transmission ECU

is faulty.

Circuit breaker CB70 OK.

Circuit breaker CB73 OK.

Both turn signals illuminate.

Engine starts.

Transmission reverse (R)

range OK.

Backup light lamps OK.

Backup light assembly OK.

WTEC III transmission controls.

WTEC III dashboard cable

assembly OK.

Rear lights cable assembly OK.

NO

Replace WTEC III transmission

ECU (para 8-7).

YES

Replace WTEC III relay K25 (para 7-9).

Faulty WTEC III relay K25.

Faulty WTEC III

transmission ECU.