Pool was running great this summer til I found motor not running. Have Sta-Rite pump and A.O. Smith motor. Found bad capacitor & replaced. When I restarted the motor it would not transition from start to run mode. I thought I had bad motor. Replaced motor, impeller and diffuser. When I started pump, it primed ok but then started to make a surging sound and I noticed the output pressure on top of the sand filter housing was only 2 psi, water was returning to pool but with much less velocity and measured motor amps which were higher than rated.(7.6 amps rated but measured 11.6)
Motor sounds normal as it is pulling water into strainer basket but when system is pressurized motor sounds like it is overloaded. Any ideas?