Ok I would start with the wiring.
If the gauges don't move it sounds like they are getting direct earths
You can buy from car builder solutions a fuel gauge matcher to enable diff senders to work with diff gauges
There are some simple tests you can try like dropping the temp sender you have in say the top of the rad when cold and run the engine for a while and as the water heats up see if the gauge moves.
If the wiring is correct you should get some readings even if there well out.
Do the gauges have live ,Earth and sender connections or a diff wiring set up.