I've got a couple of loose wires / connectors in the engine bay. Looks like they are supposed to be that way, because their tied up to nearby wires, I figure they are used for options that my XJ doesn't implement, such as the connector for the ABS.

I'm going to post pictures of each loose wire/connector and their locations. If you guys could explain the would-be function of each one, or maybe even if, when, and how much power they receive, that would be great.

This one is tied to the wiring for the passenger side headlight and hazard lights, as you can see its between the battery and the passenger side quarter panel:



And this one is towards the rear of the engine bay (closest to the windshield) on the passenger side, and hangs like that between the washer fluid reservoir and the transmission fluid dipstick:

 

Have you ever considered obtaining a wiring diagram?

 

Yes. I just posted this so I'd have something to read in case I didn't find my answer there.