The goal of this little project was to get the driver-side speaker to work. Simple as that. When operating the radio I only get sound out of the passenger-side speaker -- and not very well, either.
After determining it wasn’t anything to do with the main radio wiring in the center console, I decided to dig into the door.
Yep, there’s the problem. One of the previous owners chopped the crap out of the wiring for whatever reason. At a certain point in time this car must have had a bumpin’ stereo. At any rate, the entire thing needs to be redone. For now, we'll settle for just splicing things back together semi-properly.
There were three main wires that needed a repair: the blue, white, and black wires. A pretty straight-forward repair that included some butt-splices and heat shrinking. I was not totally satisfied with the repair due to the wire being corroded and extremely short, but it worked. After the repair the speaker began working again. Later I resolved the mystery of the spare wires – they went to the vacuum lock mechanism or some such.