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 319 of 926

TM 9-2320-283-20-1

2-11.

TROUBLESHOOTING PROCEDURES (Continued).

MALFUNCTION

INSTRUCTION

INDICATION

YES

NO

63 BOTH BLACKOUT STOPLAMPS NOT WORKING (Continued).

NOTE

Blackout toggle switch must be set to BLACKOUT

position, air system pressurized to 105 psi, and brake

pedal depressed by assistant when doing the following

checks.

7

Check for voltage at

12-volts dc

Go to step 8

Replace stop-

circuit 25B-YL terminal

nominal

lamp switch

of stoplamp switch

(Para 3-97).

Install circuit

breaker bracket

(para 3-114).

8

Check for voltage at

12-volts dc

Remove jumper

Repair circuit

circuit 25B-YL terminal

nominal

wire.

Connect

25B-YL (para

of connector

circuit 25B-YL

3-127)

Install

to 25C-YL, and

circuit breaker

go to step 9

bracket (para

3-114).

9

Check for voltage at

12-volts dc

Go to step 10

Repair circuit

circuit 25C-YL terminal

nominal

25C-YL (para

of blackout toggle

3-127).

Install

switch.

circuit breaker

bracket (para

3-114).

2-194