71 Ranchero Wiring Diagram

I’m looking for a good detailed wiring diagram so I know where to begin, don’t want to accidentally remove some wiring that I shouldn’t. 

There's enough wrong there in the wiring that you will be at it for a long time. That's why I wrote go slow and carefully. Keep cleaning things and looking it over, slowly you will get an idea of which wires are OEM colors and which are not.

I don't mean to say cut anything not stock, but some things like home wiring don't belong, and the speaker wire seen there could be tossed immediately. You should try to preserve as much of the OEM wiring as possible, that might all be useful later. The aftermarket speaker wire is low cost and you don't know how old or bad anything is.

Fortunately the OEM wiring is not very complicated or difficult to trace etc. You could manage with many different wiring diagrams of similar cars if needed. The basic systems will almost all be very alike between car models. The wiring colors will be the same or very close, which also means you should be able to locate both some old wiring, and some brand new from aftermarket sources. The actual work may require a few tools to make electrical connections etc, so so learn as you go what it's going to take.