89 Burb: passenger side taillights out! Help?

[Electricduane]

All 3 lights on the passenger side rear will not illuminate with parking lights, brake application, or turn signal. The driver side works just fine. My test light indicates no power to any of the sockets. I took the assembly loose and cleaned/reinstalled the ground wire. That does not appear to be it. I also checked the fuses. That does not appear to be it. It seems to me if a fuse were out, both sides would be inoperable.

Possible issues:

1) I recently removed the switch that turns the courtesy light on the tail gate is open. It's simply a wire with a plug-in attachment on the end of it. It's not contacting metal or doing anything weird at all. It appears to be totally separate and I don't see how this could be related.

2) I recently replaced all four of the switches that illuminate the courtesy light when the doors open. They all work fine. I also don't see how that could be related.

All advice is appreciated. I hate messing with electrical Gremlins like this.

[68Timber]

I'm not that good with the 12v but if it were me I'd put that tailgate courtesy light switch back on just to see if that fixes it. I know that's kinda like 'poke it with a stick and see what happens' idea but since it was recently removed and they're both at the rear end of a Burb, maybe somehow on a common circuit? I'm guessing out loud, but that's what I'd try.