I replaced the OEM stereo myself with success, but it seems like since then the reverse lights will not work. I've had a lot of fuses start to go, so I started there first. The 10A fuse in position 22 is for the back-up lights, but everything else controlled by that fuse (gauges, cruise control, etc) was working fine. I went ahead and replaced it anyway, but the lights still wouldn't work. I bought and installed new bulbs, but that didn't fix it either.
Is there a switch on the gear shift lever that I might have tweaked while I was working with the radio's power cables?

 

Well, after reading some more posts about wiring, I did a full inspection of the wiring in the trunk. Sure enough, a few of the wires' insulation has cracked so the copper(?) is showing, and at least one is completely severed.
So, now that I know the problem, does anyone have any advice on whether I need to replace the entire harness, or is splicing the best option?

Thanks!

 

Replacing the harness is the "best" way of fixign the problem. But honestly,its not cost effective and just plain crazy. I would cut the wires back a bit, then solder in new pieces of wire, and use heat shrink tube to cover the exposed wire/solder. Replacing the harness for such a minor repair seems a little extreme.