My odometer and trip odometer have been broken for a couple years now. The speedometer still works fine though which makes me think it's a mechanical failure in the gauge itself. I've had the instruments out a number of times and have fiddled with the gauge, but haven't made a serious attempt at a real diagnosis. Here's my logic defending the mechanical failure within the gauge: the two odometers are mechanically linked and probably (assumption #1) run off of the same input signal as the speedometer (if anyone can confirm or deny that would be great). So, if the speed/distance input signal were to fail you should lose the odometers and the speedometer. That's as far as I've gone. Hope this generates some thoughts for you.