70 up charging system upgrade question

No just the immediate path. Dont worry for now about start, accessory, etc, you are "going down one road" at a time. Power through the switch to ignition.....just two wires. What you are trying to determine, is "the drop" inside the switch, or right at the terminals of the switch/ connector? I have found at least two, over the years, where the CRIMP itself at the terminal was the problem. This is difficult to get to but THINK of them as each a separate part

This may be a poor example. What I'm trying to get at is wherever the drop changes "a lot" is right where the problem is. As you move one way or the other with your probe along that path, wherever the drop "is" will change the reading