I've got an 82lb Motorguide Digital Tour 24v and I haven't had any problems until recently. Lately, when I put it on high, it runs for a few seconds and then trips a breaker on one of my batteries (always the same battery/breaker). If I turn the speed down just below the highest setting, the motor will jerk while pressing the swtich on the pedal like the power is being flicked on and off (picture a light switch being flipped on and off rapidly). Works fine at slower speeds. I've looked under the cover, but can't see that any wires are touching that would create a short. My batteries are less than a year old. Any ideas?