10 months ago
Last edited at 3:39PM on 6/20/2013
Find a speedometer shop. If you have the skill and knowledge take it apart and repair properly. Depending where you are it may not be easy to find a shop. Try asking the parts counter guys at major new car dealers where they send the instrument panels from the cars they sell. In the time until you have a reliable gage keep track of how many miles you have traveled since fill up. You NEVER want to run a diesel completely out of fuel to prevent doing expensive damage.
In order to replace the fuel gauge, you first have to identify what is not functioning on it. Since it fell off, it could be broken and therefore you should have a professional mechanic check it out for proper fixing.