Water Pump Sorcery

[trisaiah]

OK, I got a real doozy here and I'm hoping someone could help me out...

A couple of weeks ago when we had a cold snap here in FL, my water pump started working intermittently. I have a basic ShurFlo 3 GPM pressure-sensing pump. Shortly thereafter, the pump abruptly stopped turning on entirely

The reservoir was very low so I filled the reservoir... no change.

I checked the voltage at the pump... the motor was definitely getting power.

I bypassed the high pressure switch on the pump... couldn't get the motor to turn on with direct voltage applied. It just stays totally silent.

At this point, I'm thinking bad pump, right? So I go out and buy a new pump. I wire the new pump in and it immediately works! For about 30". Then it shuts off. I'm thinking wtf...

I was running a lot of electrical equipment at the time (AC and DC), so I turn everything off and cycle my boards. And now the pump works great! I wash my dishes for the first time in weeks and the pump seems to be working perfectly.

Then I wake up the next morning... the pump is COMPLETELY DEAD. The sucker just won't turn on. Same symptoms as before. It wasn't turning on and off during the night. It just seems to not be getting or sensing power to the motor.

Sorry for the wall of text but this is really baffling. Anyone know what could be going on? Something electrical? Witches? Goblins?