Ignition Switch and Key

The ignition switch is located on the left-hand dash, below the headlight switch. See Fig..

The ignition switch has four positions: OFF, ACC (accessory), ON, and START. See Fig..

In the OFF position, the ignition switch is vertical. The key can be inserted and removed only in the OFF position.

The following functions are operable when the ignition switch is in the OFF position (regardless of whether the key is inserted):

• low-beam headlights

• taillights

• brake lights

• road lights

• dome lights

• clearance lights

• hazard warning lights

• utility lights

• baggage compartment lights

• spotlights

• electric horn

• clock

• refrigerator

• CB radio

• power mirrors

• power receptacle

• fuel heater

• electric oil pan heater

• electric or diesel-fired engine coolant pre-heater

Turn the key counterclockwise to reach the ACC position. In addition to all the functions that are operable in the OFF position, the following functions are operable when the switch is in the ACC position:

• radio/stereo system

• heater and A/C fan

• mirror defog

• windshield fan

• ether start system

• air dryer

• backup lights

Turn the key clockwise past the OFF position to reach the ON position. With the switch in the ON position, all electrical systems become operable and the warning and indicator lamps illuminate. Wait for three seconds before starting the engine.

The SAM Cab vehicle controller automatically cycles all exterior lights off and then on when the headlamps are on and the park brake is released, or set. This rapid flash of the exterior lights is a self-test to detect any bulb that is not operational. Drivers may notice all lights flash simultaneously during this process. This is the normal operating sequence. A fault code is set for any bulb that is out.

Turn the key clockwise past the ON position to reach the START position to start the engine. Release the key the moment the engine starts. Do not operate the starter longer than thirty seconds, then allow the starter to cool between attempts. If the starter overheats, the starter protection system will prevent operation of the starter until it has cooled. Release the key the moment the engine starts.

The ignition key also locks and unlocks the cab doors, the baggage door(s) and if equipped, the bunk door(s).