Before I put the harnesses in the truck, I pulled all the wires out of the bulk head and hit them with a copper wire brush, same with the blade ends on the engine bay side of the harnesses.

A loose connection was not the issue here. I tracked this back to a switch issue. I had my wife probe the contacts on the back of the ignition switches while I cycled it in my hand. I wasn't about to go about installing one until I verified it worked.