Do you mean on the left front fender? It is a LED fuel gauge. All of the lights are on when the tank is full. I have an '88 TRX350D. The gauge on mine did work when I got it but after years of getting mud, water, etc. in it, it does not work anymore. I would not trade my '88 Foreman for a new one, these are some of the toughest hondas ever built.