Hi guys, back for more advice. The driver's side reverse lamp is out. It's not the bulb or the bulb holder, as I switched it out for the other side and it worked fine over there. When I took out the bulb holder, I thought it might be a little corrosion, but then I took the bulb holder out of the tail light just below it. The corrosion was much worse there and the lamp is working fine. I put some dielectric grease on the bulb holder contact points, on the wire terminal of the green wire, and on the metal pieces on the taillight assembly. No dice.

Any ideas. All the wires coming out of the wiring bundle look to be in good shape and all the other lights on that side of the taillight assembly are working.

irollmadison,
fyi dielectric grease is insulative and not conductive. You might use it, say, around the inside walls of a spark plug wire boot in order to keep the moisture out.
My tail lights were off so often I got sick of da cops pulling me over or someone pulling along side and saying "hey buddy..."
Just recently I took out my tail lights (keeping track of where the wires return to). I just cut all the wires about 5 inches from the lamp. That way I knew where to reconnect. I disconnected the 2 ground wires of course.
Once on the bench I disconnected each wire and soldered it back to the positive side of the bulb connector it belongs to. I pulled out the flat common ground rod and did this to each ground connector as well.
I connected all the grounds together and reconnected that to its original grounding spot with the light fixture reinstalled and just rematched and reconnected the various colored wires. Worked good...kind of like solid state lighting.
Only problem I had was that I could not get one of the fog lights to work, so I ran a connecting wire from the fog light on the other side.

Update: so I realized what I described was actually the turn signal, not the reverse lamp. And at some point, I did something that made the whole drivers side assembly stop working. (But I know the lamp failure sensor is working, since i got the warning light!) So I went back in, sanded the contact points, reassembled, and now the reverse lamp and brake light work...and the turn signal has stopped working. I sanded the turn signal contact points again, still didn't work. I swapped out the turn signal bulbs and bulb holders, from driver to passenger, since the passenger was working, and then neither of them worked. Switched them back, and now it's back to the driver side turn signal not working and the passenger side working.

In short, I fixed the reverse lamp and broke the turn signal.

Run a new "hot wire" from the other reverse light to your faulty one. See if they now both work. That's some diagnostic info.