wiring issues 1980 Gmc C25

[1980Jimmyc2500]

Cant seam to find any info on my 1980 Jimmy. Having some electrical issues. Trailer wiring is not working and also fuel switch, and radio have no power. cant seam to figure it out. oh and also my trailer break isnt working. At one point these all worked. I checked fuses. but no power, can some please help? Diagrams are hard for me to read. I do better with pictures and step by step instructions. I suffered a Brain injury about two years ago and simple things like diagrams i struggle with. Thank you for your time!!