I have finally gotten my '68 rebuild project drivabe and noticed that the fuel gauge on my original instrument cluster is not working. I turn the engine on and the needle does not move. I have added 10 gals of fuel to the tank. I also took a bulb tester to the wiring connector at the rear, unclipped the tan wire connector to the fuel tank and (with the engine running) get no light at the connector. Am I checking correctly? Any ideas?