Suspension/Trailer Connection Controls
Air Suspension Dump Control Switch
Notice: Do not operate the vehicle over uneven ground such as ramps, speed bumps, curbs, etc. with the air springs deflated. Doing this may lead to air bag separation from the piston, preventing the suspension air springs from re-inflating.
The air suspension height control switch may be used to aid in connecting or disconnecting from a trailer. When the switch is set to LOWER, the air suspension dump valve deflates the air springs to lower the rear of the vehicle. In the AUTO position, the automatic ride-control valves operate for normal driving.
Notice: Never exhaust air from the suspension while driving. When the air is exhausted, the suspension will not absorb road shocks, and components may be damaged.
A red LED in the switch is illuminated when the suspension is deflated.
Fifth Wheel Slide Control Switch
Notice: Do not activate the fifth wheel slide control valve while the vehicle is in motion. To do so could cause damage to the fifth wheel member, the kingpin, the cab or trailer, and ultimately to the drivetrain.
The fifth wheel air slide valve allows repositioning of the sliding fifth wheel from inside the cab. Move the air slide control valve switch to the LOCK position to lock the fifth wheel to the baseplate. Move the switch to the UNLOCK position to unlock the fifth wheel slide mechanism, allowing changes to the total length of the tractor-trailer and changes to axle loads to comply with state or provincial laws.
For detailed operating instructions for fifth wheel slide, see General Information. A red indicator light illuminates whenever the fifth wheel slide is unlocked.
Trailer Auxiliary Switch
Some trailers with pneumatic brakes are equipped with power for the trailer lights. The connection is passed from the vehicle to the trailer via the primary receptacle, controlled by a dash switch.
Press the top of the switch to activate the trailer auxiliary function. Press the bottom of the switch to turn trailer auxiliary function off.