Replaced Rule 25S with another. The existing pump would activate in automatic mode but the rotor would not turn. Rather it would go "mhhhn". Once or twice. In manual mode the pump works fine. One for one replacement with identical item. Tested automatic function by removing strainer from WSB-500 strainer , opening engine raw water thruhull, and using that to fill the bilge. Pump removes water faster than the strainer allows water into the bilge.
Did not redo electical as I have not sited the replacement switch, a Rule 41 , at this time. Need to find a place to mount it.