Mine flaked out on the passenger side bulb wouldn't light and was good bulb, and all cleaned up bulb sockets, etc. Tested the unit that holds the bulb and had no continuity through it to the passenger side bulb. I didn't care but the dash message was annoying. The problem was internal - corrosion maybe? What I did was take the unit off, drill a very small hole directly behind the passenger side of the license plate assembly (in other words, is not visible, like the original hole on the driver's side is not visible). I put in a rubber grommet, and fed wire through the hole and internal in the liftgate over to the other hole - so maybe 8 inches or so. Tight working, but I soldered the new power wires to the original ones and soldered them directly to the applicable metal bulb-mounting points (from the back side) of that passenger side. Re-assemble and has been all good.

You said your wires wore through? I'm not picturing that and I'd think you'd toss a fuse straight away in that case. However, if you have the option of tying into the feed wires inside the tailgate, join additional to them and feed out through original hole plus a new access hole behind the passenger-side light, you can solder directly to the metal bulb socket points and be all good for about $3. (grommet and some heat shrink.)