Mount the switch in the dash, secure with the provided bezel nut, and then install the knob. Note that if the stock dash panel is being used, a shaft extension (available from New Port Engineering) will be required. Reinstall the knob and tighten in place with the set screw. Connect the power wire to the accessory circuit breaker or to the wiper motor circuit as appropriate for your truck. Connect the ground wire to a suitable ground on the negative side of the battery.