Lights flicker and gauge jumps around???

No here's the deal. Get clear back to the BULKHEAD CONNECTOR. There is only one wire, that when "running down the road," provides "run" power into the engine bay, that is, the "ignition run" normally DARK BLUE, IGN1. The PROBLEM is that with things like bad connections in the ignition switch and connector, the bulkhead connector, etc, the voltage supplied by this wire has a DROP, and this causes the VR to OVERcharge because "it thinks" battery voltage is low

So, where the blue "run" wire comes out of the bulkhead, and BEFORE it branches to anything else, cut into it (electrically.)

The blue coming out of the bulkhead goes to the relay coil to activate the relay

The relay power feed can come from a breaker or fuse off the starter relay big battery stud

The switched contact of the relay connects to the engine harness side of the blue which you cut. So now the relay is feeding power to EVERYTHING fed off that blue wire