(solved...see my own replies below)

2008 Standard Cab
Power nothing (manual windows, locks)
Purchased a few weeks ago and noticed the left door speaker wasn't working, but didn't notice the door latch not triggering any chimes/light until a few days later.

Four wires go into the driver door. Two to the speaker and two to the door latch sensor.
I read a bunch of forums and then spent a few hours trouble shooting to come to the conclusion that there is no continuity to the driver side latch sensor or speaker wires. (I temporarily swapped the latch from the properly functioning passenger door. Manually operating the latch did not have an effect on the chimes/lights. I also switched out the speaker with the good one. It did not work.)

I looked for disconnected/cut wires in the door, behind the radio, in both kick panels, and I peeled the boot back between the door and body. No damaged or disconnected wires were found.

Considering I'm only looking at four wires, would it make the most sense to simply bypass the existing wiring? Fishing a pair of wires between the door speaker and the radio harness should be simple enough.

However, I don't know where it would make the most sense to splice a new pair of wires coming into the car from the door latch sensor. If I run it too far then I inadvertently bypass a connection it needs to make. If I don't run it far enough then I don't make it past the break in continuity.

Thoughts?

 

OK, found the unclipped connector, but I'm searching for where it plugs into. I had resorted to running new wires to the radio and had removed the panels under the steering column and then removed the e-brake pedal. I was feeling around trying to fish the wire and an unclipped connector was shoved up into a crevice. Sure enough, I have continuity to the speaker wires and the ungrounded door latch sensor wire. Now I just have to figure out where it plugs in!

 

Found the other end of the connector. With all of the panels removed under the steering wheel, and a mirror, I was able to see the back end of a connector facing the wrong way and wedged up high. With my head and shoulders in the floorboard as far as I could go, I could just barely feel with my finger that the other end was empty. But, it was clipped in, and it sandwiched between two parts. No way to pop it free. The wires and clip coming from the door harness couldn't reach it, and there's was not enough slack to turn it the other way. So, after some thought, I took a small hacksaw blade, got between the bottom of the connector and the piece it was clipped into -- while my head and shoulders were still wedged under the brake pedal -- and I sawed the plastic retaining post off. Once free there was plenty of slack to connect them. I zipped tied it out of the way, checked the speaker and the door latch, and problem solved.

I know from the service records that the previous owner had the heater core replaced, and I believe it's necessary to pull the entire dash. Indeed, I could see some evidence of where the dash had been removed. I think what happened is that they pushed the connector into its retaining clip hole facing toward the driver rather than the floorboards. When the dash was reinstalled it wasn't possible to clip the other end into it. So, they just left it that way.