Very Confused!

Maybe someone can chime in on how to test a regulator.

We can bring the battery in for load test.

Not sure which alt you have but I have a nice clean one that looks to be SWEET on the shelf.

I probably have some welding cable with some 1/0 connectors we can crimp on.

Open to more suggestions of what to check besides the grounds. Im just a guy with a multimeter and a couple wrenches.