Originally Posted by papajam
Yes, of course. 1972!
The diagram shows that your Jr. is powered by a single 10ga red wire from the starter to the fusebox. I check for battery voltage at the starter. If less than the voltage at the battery, I'd suspect the positive battery cable/connections. If the voltage is okay at the starter, check the voltage at the largest red wire on the back of the fusebox. If less than battery voltage, there's a problem with this wire or it's connections. If voltage here is okay, back to the drawing board.
If you'd like a color wiring diagram for your Junior, PM me your address and I'll email it to you.
Thanks for this.....I think this is exactly where the problem lies. The single red wire you mention must be the loose one I found. I could not find the other end, but it could very well be the connection to the fusebox, as it disappears into a loom that goes "where no man gone before".