These are basic checks if the pump will not start:
- Verify that the voltage coming in is correct. Measure line-to-line.
- Make sure that the shaft spins. You can access it from the back if you remove the capacitor and slip a 7/16" wrench on the shaft. Or, you can open the pump and spin the impeller clockwise.
- Check the contacts on the centrifugal switch to make sure that they're clean. Copper V strips visible at the back. See Pump Centrifugal Switch.
- Replace the capacitor. Make sure to tuck the wires back in between the posts. If you leave them outside the posts, they can get snagged by the centrifugal switch weights. See Pump Capacitors