Well, I finally decided to tackle this. We have a 2 year old that is fascinated by the vanity lights, and he will stress things to the point of failure by repetitive action. The vanity lights in my 2006 GS430 decided to quit working on both sides. I figured it was the bulbs and replaced those with flank LEDs from V-leds. I also checked the fuses just to make sure, although the dash lights still worked fine.

What you need:
Several thin blade flat head screwdrivers (one will work, but two make prying the assembly MUCH easier).
One Philips head screwdriver to take the sun visor out of the car (not necessary, but makes life much easier to work inside where it's warm and a stable surface).
A multimeter with the ability to read continuity
A box of 2" x 4" industrial velcro (about $5 at the Office Depot here)
A box cutter with a really sharp blade.
Cut proof gloves if you are as clumsy as I can be when I get in a hurry.
An understanding that this can result in a cracked mirror or torn upholstery on the visor if you don't take your time.
Enough "intestinal fortitude" to attempt this repair.

I figured if this was assembled the same way most things are on the car, then the mirror assembly an track would pry out. It does once you slide the mirror door open a bit. There are two tangs on the door that hold under the upholstery. That took me some time to realize. You will want to pry on the plastic trim NOT ON THE MIRROR ITSELF. If the mirror slides open to the right (driver side), you want to pry on the left side of the plastic assembly. There are two tangs holding it in place on that side. Once it releases get the mirror just high enough to clear the upholstery. Work slowly here to make sure you don't stress the mirror too much, or pull the upholstery free of the visor. The entire mirror assembly slides out, including the track for the door.



I took this photo by working my iPhone camera into the cavity so I could see what is going on. Turning on the LED light and using the video camera feature will really give you a good idea of what the internals look like you can't normally access without destroying something.

It turns out there is a paddle switch on the inside of the sun visors that controls the lights. The visor has to be down, and the mirror open for the lights to be on (normally). I took a photo of the inside of the visor assembly. The switches are toward the top of the visor on both the driver and passenger. This took a bit of poking with a non-conductive tool to find the switch ( I used the handle of a toothbrush), and my multimeter to watch the resistance across the terminals on the white plug where it attaches to the car. The white plug comes off the base to make access to the terminals possible (I don't have needle probes that small). This will be important after you put the velcro in place. It will confirm if you got the fix right, or if the failure still exists (always on or always off).

The fault appears to occur because the little contact behind the big copper paddle switch gets bent out of the way. I decided the easiest way to repair this was using the soft side of the industrial velcro. This stuff has a really strong adhesive on the back, I put it on the edge and top of the door to push the switch about another 1/8 inch into the contact. The soft side also doesn't hang on anything in the mirror. Make sure you trim the velcro so that it does NOT wrap onto the backside of the mirror door.

You are ready now for reassembly. Slide the mirror back into the housing with the mirror door slightly open. It will snap right back into place. Move the mirror mount so it would be "down" in the car, and the visor is not extended. Once the mirror is in, open the door all the way. The multimeter should go from "overload" or infinite resistance, to reading nearly zero resistance. Close the mirror door to make sure it goes back to overload. If it doesn't you will have to remove the assembly and use the bristle end of the soft brush to slightly separate the contacts.

Reinstall the sun visor and enjoy!

The whole project will take about 30 minutes, even chasing the baby around the house.

YMMV

Reinstalled:


Visor down, but door closed:


Visor down, and vanity mirror open:


Let me know if you guys want different pictures, or of the interior of the assembly.

 

Nice write up, im sure it'll help someone with the same problem..