In this video I go over how to wire up a 4-wire standalone harness to a GM Bulkhead. It should cover all GM bulkheads for 73-87 trucks, K5 Blazers and Suburbans.
Keep in mind I'm uncertain about the wire I currently have on the alternator running into the bulkhead but the others are correct. I wired this after searching many GM diagrams and if anyone has wired theirs different, please point out the differences in the comments. Please subscribe for more progress and how-to videos in my LS swap frame off restoration on my 1980 K5