Pressure switch and pump pulseon/off rapidly
System is 11 yrs old, never a problem. Seasonal irrigation from a ditch. Ran fine for first day of season then started rapid pulse; pressure switch is clicking, pump is going on/off, then pump got too hot and turned off by itself. Replaced pressure switch, no change. Though pump bearings going out, replaced whole thing, Myers 1.5HP QP, SAME DEAL. All zones cycle through fine on gravity. I don't know what else to replace, or what's out of whack.