Axle Switches
All axle switches contain a red LED that illuminates the switch from within when the switch is turned on (the upper part of the rocker is pressed). The legend under the LED, if any, is not visible until the switch is turned on.
Important: A guard is positioned around all axle switches to prevent unintentional activation.
Note: For more information on axle switch function, see Driving Precautions.
Differential Lock Switch
Notice: Differential lock should only be engaged when the vehicle is stopped or moving slowly at low throttle. This will prevent internal axle damage.
The differential lock switch is a two-position guarded rocker switch. It causes the wheels on each axle governed by the switch to rotate together. It is also known as side-to-side wheel lock. See Fig..
Fig. 1, Differential Lock Switch
To lock the wheels together, press the upper half of the rocker switch momentarily. To turn off differential lock, press the upper half of the rocker switch again.
When the panel lights are on, the double-axle icon is backlit in green.
Important: The differential lock switch is guarded to prevent unintentional switch activation. If the LED in the switch begins to blink during normal operation, when the switch has not been activated, this indicates an error condition. Take the vehicle to an authorized Freightliner dealer as soon as possible.
Interaxle Lock Switch
Notice: Do not turn the interaxle lock switch on when the tires are slipping. Do not continuously operate the vehicle with the interaxle lock engaged during good road conditions. To do so could result in damage to the axle gearing and excessive tire wear.
The interaxle lock switch is a two-position guarded rocker switch installed on vehicles with dual drive axles. It causes both axle shafts to rotate together. See Fig..
Fig. 2, Interaxle Lock Switch
To lock the axles together, press the upper half of the rocker switch momentarily. To turn off interaxle lock, press the upper half of the rocker switch again.
When the panel lights are on, the double-axle icon is backlit in green.
Important: The interaxle lock rocker switch is guarded to prevent unintentional switch activation. This switch does not have a diagnostic blink function when inactive.
Backup Alarm
The backup alarm sounds when Reverse (R) gear is engaged. Check the operation of the backup alarm daily (if so equipped).