MasterCraft MMDC Box All of your gauges now working? Your MMDC box is most likely the problem. Replace your MasterCraft MMDC Box and get everything back to working! This MasterCraft MMDC Box is direct from MasterCraft and will work with all MasterCraft boats from 2005-2006. Please note: compare to your existing before installing. Installed MMDC Boxes will not be authorized for returns.