I have a new submersable 110vt. Well pump installed and wired correctly. Unfortunately, the pressure gauge will suddenly fall to zero woth no water pressure. Have checked all power to switch and fuses. No problem. But you can hear the pump come on for about 3 seconds then quit about every ten minutes. Have changed switched and checked the points. Even checked tank pressure. Can't figure out why it just cuts on for a moment then quits. Got any ideas. This has been going on for months. It's a weekend Mountain home that is used rarely.

Check the switch and see if the points are opening when the pump cuts off. If the points are still closed, but the pump shuts off, then the switch is not likely to be your problem.

You have actually described a second problem, that of the pressure just falling to zero for no apparent reason. Has this been happening ever since the pump was installed?