How old is the vehicle? These Peg Perego vehicles have a small motor behind each rear wheel that can wear down over time and draw more power. This overheats, squeals, and/or trips the breaker. If you're sure the battery is good and there's no corrosion or water damage on the wires, I'd look into getting a pair of new motors. Light Electric Vehicle Technologies might carry them, as well as "The Super Kids" or other places.