I've notice a few members having trouble chasing down electrical problems. These pages from a 1975 Repair Manual contains info on all the wiring and wire colors. There are additional pages of text and details of lights, the Univolt, and other peripheral equipment. PM me if you think you need them.
These images were reduced to 800-1200 pixels wide from original scans 3000 pixels wide. If these are not sufficiently readable, let me know.
I assume the electrical system was pretty similar across all of the 1970s. And thanks to those who motivated me to look in the book--I found answers to problems I didn't realize I already had the answers to!
Fuze block photo and schematics:
Seven-way trailer hitch connector--standard over all years
Main Charge Line
23' and 25' models
27', 29', and 31' models (mid bath)
27', 29', and 31' models (rear bath)