Is the whole gauge not working or is it just the speedo not working, i have a simular problem my gauge doesn't read at all it's just a dark screen, but the other things like reverse and high temp, and brake, lights still work. i've noticed that sometimes it works after ive rolled it and if i roll it again it stops working; i've checked all the electrical connections and they're all good, so now i think that its something in the gauge it self. But if it's just the speedo not working start at the sensor and work your way to the gauge checking all the connections. Hope this helps.