Have some Lights, but not others, Help!

"step down ??" Are you talking about the instrument voltage limite? That only feeds the gauges. But PC boards can develop problems AND THE ONLY GROUND for the cluster is when mounted, through the screws. Good idea to provide a separate ground pigtail for the cluster

Here's an old repair thread on clusters:

Printed circuit pins repair

Also, please don't depend too heavily on the aftermarket diagrams at MyMopar. They leave out many details/ options/ connectors. There's a 73 shop manual there, and it and some others by the way, came from the guys right here