Dash Cluster Question - 68 Barracuda

I bench tested mine using a battery charger for power. Be sure to use the right circuit. Continuity tester is a great help. .
also used the battery charger to test. But ended up rewiring the whole car, didn`t want 49 yr old wiring in it. Also bought a limiter off ebay and a new sender. It works , but is slow as molasses getting there ! ???