Cab pump solenoid switch (Part 112906) used on Capacity terminal tractors and yard trucks to control the electrical actuation of the cab hydraulic pump solenoid. This switch completes or interrupts the electrical circuit for the cab pump’s solenoid coil so the pump can be turned on or off from the operator’s control panel. It installs in the operator cab, typically on the dash or control console. When the operator toggles this switch, it sends voltage to the solenoid of the cab hydraulic pump, energizing it so the pump begins moving fluid.