TM-9-2320-283-20-1

TRUCK TRACTOR, LINE HAUL, 50,000 GVWR, 6X4, M915A1

TECHNICAL MANUAL; ORGANIZATIONAL MAINTENANCE PART 1 OF 3

DECEMBER 1983

TM-9-2320-283-20-1 - Page 325 of 926

TM 9-2320-283-20-1

2-11.

TROUBLESHOOTING PROCEDURES (Continued).

MALFUNCTION

INSTRUCTION

INDICATION

YES

NO

65.

BOTH BLACKOUT TAILLAMPS NOT WORKING.

NOTE

Headlamp switch must be in ON position and blackout

toggle switch in BLACKOUT position when doing the

following checks.

1.

Check for voltage at

12-volts dc

Go to step 2.

Refer to mal-

circuit 30-OR terminal

nominal.

function 44.

of headlamp switch.

2.

Check for voltage at

12-volts dc

Go to step 3.

Repair circuit

circuit 30-OR terminal

nominal.

30-OR (para

of blackout toggle

3-127).

switch.

3.

Check for voltage at

12-volts dc

Go to step 4.

Replace black-

circuit 23Z-TN terminal

nominal.

out toggle

of blackout toggle

switch (para

switch.

3-79).

4.

Disconnect 23L-TN from

23S-TN at connector

and, go to step 5.

5.

Check for voltage at

12-volts dc

Repair circuit

Repair circuit

circuit 23L-TN terminal

nominal.

23S-TN (para

23L-TN and/or

of connector.

3-127).

23S-TN (para

2-200