Inspection and Test

TM 10-3930-633-12

pressure switch in the brake system and is

terval, check headlights, stop and taillight, and

illuminated whenever the brakes are applied.

back-up lamp for proper operation. Check for

secure mounting of light assemblies and switches,

c. Back-up Light. The back-up, lamp is

mounted in the same way as the stop and

and make certain the wiring and connectors are

taillamp, and differs only in having a clear lens,

clean, tight, and well-insulated. The plastic lenses

in the rear lights may become discolored due to

rather than red, and a single filament bulb. The

age or exposure to contaminants. If discoloration

lamp is controlled by a switch on the instrument

is apparent, the lenses and gaskets should be

panel.

replaced.

d. Horn. The tractor is equipped with a single

b. Horn. At each quarterly maintenance in-

electrical horn, mounted to the cowl plate inside

terval, test the horn for proper operation. If horn

the engine compartment. The horn is controlled

is inoperable, replace the horn fuse or relay. If

by a horn button in the center of the steering

horn tone is weak, check wiring connections for

column. When this button is depressed, a horn

secure connections and replace horn if required.

relay is energized to sound the horn. An in-line

Check all wiring to make sure that wiring and

fuse for the horn circuit is included in the wire

connections are clean, tight, and well-insulated.

from the ignition switch terminal to the horn

relay. The horn relay is mounted on the cowl plate

4-45. Replacement

beside the steering column.

a. Headlight. Refer to figure 4-19 and replace

e. Wiring. Refer to Section IX, Maintenance of

sealed-beam headlight parts as required. Make

Electrical System for the wiring diagram showing

certain that wiring connections are clean and

wire routing and color codes for the lights and

tight after installing a new sealed beam lamp.

horn.

4-44. Inspection and Test

a. Lights. At each quarterly maintenance in-