KEY TO CONTROL PANEL (Cont) - TM-9-2320-273-100064

TM 9-2320-273-10

KEY TO CONTROL PANEL (Continued)

TRAILER AIR SUPPLY CONTROL

(M915, M916, M917 AND M920)

Supplies air to trailer air reservoirs. Push in to supply

air to (charge) trailer reservoirs; pull out to shut off

air to trailer. If tractor air system pressure drops to

60 psi, the trailer air supply protection valve will

trip, fully applying trailer spring brakes.

BACKUP ALARM OVERRIDE

(M916 THROUGH M920)

Before backing operations, make sure the backup

alarm override switch is in the down position.

DO NOT DISABLE THE ALARM AT TIMES

WHEN PERSONNEL OR EQUIPMENT SAFETY

MAY BE SACRIFICED AS A RESULT.

Place this switch in the up position to turn off the

backup alarm when backing in "Quiet Zones"

Return the switch to the down position to activate

the alarm circuit.

STATIONARY WORKLAMPS SWITCH

(M916 AND M920 ONLY)

Place this switch in the ON position to turn the work

lamps on, and the OFF position to turn them off.

ENGINE RETARDER SELECTION SWITCH

Selects the number of engine cylinders desired for

the braking action. HIGH position provides maxi-

mum engine braking (6 cylinders), MED position

provides braking on 4 cylinders, and LOW position

provides braking on 2 cylinders.

TA 073553

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