General Description, Cab Load Disconnect Switch
Warning: Turning the cab load disconnect switch (CLDS) to the off position does not disconnect power to all electrical components (e.g. the starter and sSAM). To work on the vehicle safely, the negative leads must be disconnected from the battery.
Important: The ignition should be turned off before turning the cab load disconnect switch on or off.
Note: If parking the vehicle for more than two days, turn the cab load disconnect switch (CLDS) to the OFF position.
If parking the vehicle for more than two days and the vehicle is not equipped with a CLDS, or if parking the vehicle for more than five days, disconnect the batteries.
Even with the CLDS off, the vehicle draws a small amount of battery power.
Disconnecting the batteries when parking the vehicle for extended periods prevents battery discharge and helps prolong battery life.
The cab load disconnect switch (CLDS) is an optional switch that can be used to open (turn OFF) or close (turn ON) circuits between the battery and the battery cable access box (BCA).
A vehicle in daily use would have the CLDS turned ON. When the CLDS is set to ON, a red LED indicator at the base of the switch selector illuminates. See Fig..
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LED Indicator Light
Fig. 1, Cab Load Disconnect Switch
The CLDS should be set to OFF if the vehicle is going to be parked for more than two days. Turning the CLDS to OFF minimizes the power draw on the battery, preserving battery life and the ability of the vehicle to start after being parked for an extended period of time.
The CLDS may be mounted in a variety of location, including:
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inside the cab on the outboard side of the driver's seat;
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behind the cab on the driver's side;
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at the battery box;
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outside of the cab.
If the CLDS is turned to the off position while the vehicle is running, the emergency power system will activate. The powertrain power distribution module will receive power from the emergency power feed, but the batteries will not be charging. See the section on Emergency Power for details about vehicle behavior under these conditions.