Could be a stuck switch. There's one on the shifter, probably one on the bow, maybe one on the steering column. Start at the shifter, have someone turn on the breaker while you push the switch down and up, may have to push it pretty hard. Check each switch.
Don't leave the pump on long.
After manipulating each switch, if you don't find one stuck, it could be a relay on the engine. Good luck.
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