From the time I got the truck, none of the four smaller gauges (Oil Pressure, Gas, Charging, and Temperature) work. The previous owner installed a Sunpro three gauge set. The Coolant Temperature and Oil Pressure guages are hooked up and are working properly, though the backlights aren't hooked up. The Voltage gauge is not hooked up. I don't know if the original gauges are just not hooked up, or if they're damaged. I have to guess with the gas gauge, so I fill it up every time I drive it. It has both gas tanks, but just the rear is operable. I have everything I need but voltage, so it hasn't been a top priority, until now.