99 Tahoe wiring help.

Well since the site is being saved, time to start putting it back to use. I've been struggling with a couple questions lately and could never pinpoint where to ask them. I've been using a lot of google, but found no real help on this one so far.

I have a 99 Tahoe, 4 door, 2WD, 5.7. During relocating the main harness on the drivers side (due to wheel tubs), I unplugged the wires from it that are located inside the cab. I have 3 plugs that run together down the drivers side door sill and plug in. 2 of the plugs will only plug into 1 location. The third plug is a single purple wire and it will plug into 5 different locations. Anyone know the correct one or what that wire is for?

My complete guess is that it is an accessory power wire and that all 5 plugs will supply power and that is why it fits all of them. I'm not confident enough to just plug it in though.

on my 99 2 door. on the top right of the block, there is a pin labeled blk. my purple wire plugs directly beneath the blk pin. its labeled nat.

Thanks man. That's exactly what I needed to know. I appreciate it.