Some of you may have wondered why the factory rear e-locker switch doesn't light up, even though it has a bulb inside. After some research, turns out the Tacomas did have the illumination wired into the harness from the factory. Here is a write-up of how I added that to mine.
First, remove the 4 bolts and the lower panel under the steering column that will give access to all the wires. You can then push out the e-locker switch from behind and pull it out enough to remove the plug. Put the switch to the side for now and you should have a 5 pin plug with only 2 wires going to it. You will see it in the upper right of this photo (I pulled it down below to work with it easier).
To complete the harness you need 2 more pins that will fit the plug. You have a couple options here:
You can go the expensive but easy route and get the pins with pigtails from Toyota, part# 82998-12170 (you will need 2).
Or you can track down the pins on the web like I did, there are a few sources out there. I ended up using a place called Eastern Beaver, they are from Japan so it takes a while to get the parts but they were really cheap. The pin you are looking for is Sumitomo 1500-0110, they are HM-MT .090.
Here is a photo of the pin:
And here you can see the pin from the wiring manual:
If you got the ones from Toyota then you are good to go, otherwise you will need to crimp pigtails in each of your pins. I made mine about 5 inches long since I saw where I was going to splice them in - before you cut your pigtails make sure you know how long you will need to the source you are going to use for illumination.
Up under there tucked away were 2 plugs that on my truck were not being used for anything. I don't know what they are for (if anyone knows let me know and I can update this accordingly) but I knew from looking at the wiring diagram that I was looking for a green wire and a white with green stripe wire for my positive and negative illumination. I found both on one of the plugs and tested them with a multimeter to make sure I got +12v when the lights were turned on one click (turns on dash lighting and parking lights). Here are the plugs that were not plugged into anything, I used the black one - you can see the green wire on the left and the white with green wire to the right of the middle of the plug.
*Update* the white plug is for the power mirror switch if installed in the dash (thanks phattyduck).
Now take your pigtails (I spliced an extra pair of wires so I would have illumination wires available for future switch mods) and splice them into the green (positive) and white with green stripe (negative) using whatever you are comfortable with. I used green for the positive and a light gray for the negative to sorta follow the stock wire color scheme; you can use whatever wire you have. You can cut and solder, or just use the little plastic clip on wire taps like I did. I actually got ahead of myself and later realized I didn't take a photo of the splices themselves, sorry about that.
Once spliced in, you use a tiny screwdriver or sharp object to pry up the little white clip on the back of the 5 pin e-locker switch plug. This allows the clips to slide in easily (you may not have to remove this just to pop them in, I had it out because I removed one of the pins to compare to the new ones I got for verification). Looking at the plug as show in the next photo, the leftmost hole is position #1 and the rightmost hole is position #5. The switch wires are in positions #2 and #5. Insert the pin attached to your positive wire into the #4 position and the pin attached to your negative wire into the #3 position.
Feed your newly wired plug back up to feed through the hole for the switch and plug your switch in. Now you can turn on your lights and see what should have been done from the factory in the first place! By using the wires I used the switch light will brighten or dim based on the illumination knob on your dash that controls the rest of your dash light levels.