mustang wrote:
We recently lost water pressure from our submersible well. Upon
inspection I found the pressure control switch to be completely
blackened by soot. I assumed a bad switch, so I replaced it. The new
switch cut in fine, but at cutout the switch started arcing rapidly,
followed by a big flash and bang. So that's what happened to the old
switch! Pressure settings are correct, bladder pressure is correct,
tank has been drained, etc., but very rapid cycling at cutout pressure
remains. Any ideas? Bad controller, low water, leak in pipe?

No expert here, but it almost sounds like the starter winding is being
chattered by something, possibly inside the motor itself, when it shouldn't
be. Might be worth calling a shop and asking their opinion.
Any possibility it got miswired prior to the first time it went out?

Pop`