Our Champion 10 hp compressor will not start automatically. You have to manually press to start it and it shut?

Our Champion 10 hp compressor will not start automatically. You have to manually press to start it and it shuts off when you stop pressing it. What may it be?|||There is a mechanical switch that turns it one when it reaches low pressure setting and turns it off when it reaches the high setting. Yours is bad. Follow the smaller air line that goes into a box, generally that is where the switch will be located. If it's an electric model, the power lines will go into the same box. When you find it, make sure the power is off before opening the box.