For the Grand:
I checked fuses - all good.
Replaced the brake light switch - no help.
Replaced the bulb housing (known problem with these WJs) - no help.
Completely removed the tail light lens housing that was the original problem (passenger side). I figured there might be a short in there somewhere that was f-ing up the whole system - no help.
Now I'm completely clueless as to what it could be. I'm no electrical genius. I have a ? in on jeepforum. com. We'll see if I get a good answer.

The weird thing is that the drivers side and the third light on the hatch were working fine until I replaced the bulb on the passenger side. Then all three went out. WTF! Sure seems like a fuse went out, but I can't find one that's bad.

For the TJ:
Simple headlight switch replacement - $25. The bitch has 165K miles. She deserves a new headlight switch after all the abuse I put her through.