64 valiant gauge problems

No fuel + no temp = bad cluster limiter. On the back of the gauge cluster there is a little metal can roughly the size of a Chiclet that plugs into a socket on the board. This little gem regulates the current through the gauges and when it goes bad the fuel and temp gauges no worky. You can replace it with a spare or make up an electronic one for less than 10 bucks in parts. There is a thread here that explains how to do this. Try a search for electronic cluster limiter or wait for redfish to chime in. Sorry I'm no more help than this....