For my two bits worth, I'm not sure the picture Dshaver shared is much help, because it's not easy to see what's connected to where. Besides, this is a picture of a two-battery setup, which may be confusing if your application is only a single battery, as many if not most were.
I think the best suggestion was to look at the wiring diagram in the owner's manual, and see if you can make sense of the connections from that. Note that the standard is that Red connects to the positive pole of the battery and black to the negative. Also, positive (+) and negative (-) should be plainly marked on the case of the battery itself near the connections. If the battery cables are original, the Positive wire should be red and the negative should be black.
If you don't have an original manual, with a wiring diagram, someone on this forum could point you to one of the same or close to the same year, if you give us the year and model of your Hi-Lo.
1999 22L Classic
2008 Toyota 4Runner V6