None of my factory gauges work 65 dart gt

On the fuel and temp gauges, I think I'd start by removing the sender wire and connect it to a good ground. Then turn the ignition switch to the on position for a second or two to see if that gauge now moves. Don't leave the ignition switch on as it may burn out the gauge. Just on long enough to see if the needle moves. If they now move, you have a sender problem. If they still don't move, I'd pull the instrument cluster and bench test EVERYTHING. You can easily check the speedometer now too by spinning the input shaft. I'd also check (and probably replace) all the light bulbs too while I had the cluster out. It's not all that hard to pull on a '65 Dart. Just make sure you disconnect the battery before you start.