Where do I hook up power

In my very very limited electrical knowledge that will soon grow, I have located one wire on the 66 Monaco that I assume is the ground cable for the battery, and cant find squat for the positive cable. I want to get power going through the system so I can test out what works and what needs a fixin before I slap the engine and trans in soon. I have a pic of the wire and where it ends up on the firewall. So is my guess correct? Where should the positive cable be? I dont know, and would really...

Where do I hook up power
Author: Dylan Galvin