t2d2

iTrader: (8)

Referring back to post #10, I haven't made any real progress in figuring out the window switch wiring, but at least I know more now about what I don't understand... The pass. switch wiring seems to correspond fairly closely to that of the driver's switch, so I figured power and ground go solely to the driver's switch and then it sends the necessary up/down signal to the pass. switch.

At the pass. switch, green/yellow and red w/ silver dots both go to the window regulator, while green/white, light blue (power), and red/blue head back into the cabin. The latter fits with my earlier guess that red/blue = pass. up and green/white = pass. down on the driver's switch.

I de-pinned the light blue (power) on the pass. switch, testing a hunch that it's only for the LED. Sure enough, the window still functions. The bizarre way these windows work is apparently that it applies power to one direction and ground to the other, and vice versa to go the other way. So, power and ground aren't needed at the pass. switch if they're transmitted through the green/yellow and red/silver wires to the regulator.

However, I tested all the combinations of jumping those 4 pass. wires (2 to the cabin, 2 to the regulator) and none resulted in a functional pass. window. The oddball was jumping green/white to red/blue, which operated the power locks even though they're on a separate set of wires. The rest did nothing that I could observe.

http://us.lexusownersclub.com/forums...window-switch/

There's gotta be something goofy there that's escaping me. Toyota over-complicated this by several magnitudes... Additionally, I took apart a pass. window switch (if you've ever tried disassembling these switches to clean the contacts, you know they weren't designed for ease of maintenance; good luck not breaking tabs), thinking I could leave just the inner white plastic piece plugged in instead of the whole black outer piece and toggle switch, but doing so resulted in a non-functional pass. window. That had me stumped, as all that was removed was plastic bits, i.e., stuff that wouldn't affect the electrical circuit. I even added back in the two metal rockers that contact the contacts, just in case they had to be touching one side at rest or something silly. The LED lit up, so it had power (later confirmed by today's test of de-pinning the light blue wire).

Can anyone think of anything I haven't tried? This is looking like a system that was designed to be very difficult to tamper with, but I haven't given up yet...

Edit: I took the next step of dissecting the remainder of the disassembled, non-working switch, to see what I could make of the circuit board traces that are buried between plastic sections. I thought that might shed light on which wires are supposed to connect to what, but that yielded a 'yikes' moment... There are four solder points from either end of the two rockers to the circuit board. One doesn't seem to go to anything, two converge at a tiny chip of some sort, then feed into a slightly bigger chip, and the fourth goes straight to one of the pins. There's more going on on the other side of the board that I can't see. No wonder it's so hard to figure out which wires to jumper in order to pass the cabin signal to the window regulator!

So, I took apart another spare switch -- my overflowing garage is trying to tell me I have far too many spares of everything -- on the off chance that the previously disassembled one either never worked before I took it apart, or somehow got damaged while doing so. I was able to get both the toggle switch and black housing off without breaking anything this time, and this partial switch has the window still functioning. Barring any "aha!" moments, that's probably what I'll stick with for ~1/3rd less bulk to conceal.