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 268 of 926

2-11.

TROUBLESHOOTING PROCEDURES (Continued).

MALFUNCTION

INSTRUCTION

INDICATION

YES

NO

45.

DIMMER SWITCH INDICATOR LAMP NOT WORKING

NOTE

Blackout toggle switch must be set to NORMAL position,

headlamp switch must be set to ON position, and dimmer

switch must be set on high beam when doing the following

checks.

1.

Disconnect circuit

28A-DG from 28B-DG at

connector, and go to

step 2.

2.

Check for voltage at

12-volts dc

Connect cir-

Repair circuit

circuit 28A-DG (pin G

nominal.

cult 28A-DG

28A-DG (para

of connector).

to 28B-DG, and

3-127).

go to step 3.

3.

Remove bulb from lamp

socket (para 3-87),

and go to step 4.

4.

Check for voltage at

12-volts dc

Replace bulb

Clean socket

circuit 28B-DG terminal

nominal.

(para 3-87).

and/or repair

of socket.

circuit 28B-DG

(para 3-127).

TA 236880

2-143