Connections in the plugs, connections at the batteries, as well as bad breaker will cause it to trip on high. On high, the current isnt pulsing, but feeding directly full time to the trolling motor. On the MK 80, you need a 60A breaker. It will draw apx 55A on high.JohnJones Trolling Motor Services870 773 3474Motorguide/MinnKota/PowerPole/Lowrance/Humminbird