My engine warning light repeatedly comes and stays on. Problem is intermittent and can go weeks without happening. By connecting a 2nd, 12V scooter battery in parallel, Pos to pos and neg to the front wheel nut, (as in jump leads) the warning light disappears. This may last a few days before the problem re-appears. Sometimes, very rarely, and not always when warning light is showing, the engine won't fire, but usually starts fine even with warning light on. Scooter runs perfectly with or without engine symbol showing. I have put in a new battery, but still happens. Taken off seat but can see no loose wire or connections.