My submersible well pump is cycling.It starts then stops turning after a few seconds, tries to restart after a few more seconds, pumps a spurt of water, stops,etc. This is with zero back pressure and the drain valve before the check valve at the well head open . Service voltage was checked: 250volts (one-phase). The breaker does not kick out. I shut it down after several cycles to avoid further damage. Please comment.

It sounds like the start capacitor and or relay is bad. If your control box looks like the picture, the best thing to do is pick up a new box. The front just pulls off after removing one screw. Then, you "plug" another front on. The front has all of the controls.

If you don't have a control box, then you have what is referred to as a 2 wire pump. All of the controls are on the pump in that case, which means that you have to have the pump pulled out. At that point, you either replace the motor only, or the pump and motor.

One other thing to check... check the voltage at the contacts in the pressure switch. You should have 2 hot wires coming into the switch from your breaker. Test those first by touching both leads with your probes at the same time. Then, test the other leads that go to the pump. Usually it is easiest to just touch the screws with your probes.

Keep us posted.
Al

Attachment 11611

Sound like you need a new control box