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 299 of 926

TM 9-2320-283-20-1

TROUBLESHOOTING.

2-11.

TROUBLESHOOTING PROCEDURES (Continued).

MALFUNCTION

INSTRUCTION

INDICATION

YES

NO

56.

BOTH STOPLAMPS NOT WORKING (Continued).

11.

Disconnect turn signal

switch connector, and

go to step 12.

12.

Check for voltage at

12-volts dc

Go to step 13.

Repair circuit

circuit 25D-RD of

nominal.

25D-RD (para

connector.

3-127).

13.

Connect jumper across

circuit 25D-RD to

grey-black circuit,

and go to step 14.

14.

Check for voltage at

12-volts dc

Connect circuit

Replace turn

either circuit 36C-DG

nominal.

36C-DG and

signal switch

or 37C-YL terminal of

37C-YL to

(para 3-80).

connector.

circuit 25D-RD.

Replace both

stoplamp bulbs

(para 3-96)

and/or clean

socket con-

nections.

57.

ONE STOPLAMP NOT WORKING.

NOTE

• Blackout toggle switch must be set to NORMAL position, air system pressurized

to 105 psi, and brake pedal depressed by assistant when doing the following

checks.

• Faulty right stoplamp is shown in this procedure. Apply similar troubleshooting

technique for left stoplamp.

2-174