Trust me, don't install any switch. It is not a problem to just steer it where you want. When you get off course enough light on e-drive indicator will start flashing meaning e-drive is disenguaged. When it recognizes next pass as you line up it will enguage and light will stop flashing( If you have it set to auto engage), it will work on next pass without pushing any buttons. That way you can watch your sprayer or implement while turning instead of pushing buttons.