2008 Volkswagen VR6 Eos
The max output of the auto dimming mirror is 1.2v. Not sure if sending 2-3 volts to the door mirror is a good idea. Rather than build your own sensors, why not just install a auto dimming rear view mirror? You can simplify the process, that is, forgo a reverse lockout and a dome light lock out, that leaves you with just a switched 12 volt and ground. Both are available in your map light assembly. You would then just need to route two wires over to your door (for the auto dimming door mirror). I could probably build you a auto dimming mirror with a non-auto dimming mirror bracket but I would suggest going with the OEM mirror with the RLS bracket and installing a new mounting base on your windshield, already discuss this with AKU, check that thread.I searched everywhere for info on the extra wires. All I could find was a reference that 13 wires passenger and 11 wires driver were for top of the range powerfolds. They are supposed to have come from the same EOS but MY07 wiring diagrams don't show the changes Thanks for pointing me to the Golf I'll try and find a schematic. I had measured across random pairs and couldn't get any XY feedback, but I had no diagram to tell me how they are wired. It's a function I probably won't use. If you can PM me the diagram pin connections, that would be helpful.
You need to be careful with the 'simple concept'. The door lock motors are driven with impulses. The powerfold motor is still small but more powerful than the XY tilt motors. It's normal running current is about 0.6A, but shoots up to over 1.5A on stall. If you don't incorporate over current detection I think it will easily burn out and defeat the whole point of doing the mod. The simplest wiring I'm suggesting for powerfold is 3 wires, 1 ground, 1 permanent +12 volt, 1 switched 12V from ignition 'on'. They are all there AFIK. The complication comes when manual operation is required from their console switch. It's doable but would need 1 or 2 wires to link between the two doors. It's probably useful to drive through narrow gates or park in narrow spaces on ferries.
The electrochromic dimming is interesting. Don't try connecting 12 Volt!!. It behaves like a very large capacitor and needs 2-3 volt at 200-300 mA to fully darken. When you remove the power source, they take a few seconds to recover back to normal, which implies if you aren't using them and there's no connection through the controller, they should be bridged with a discharge resistor. They are probably using pwm to control the dim. I thought about building my own front and rear facing light sensors but can't be bothered with the hassle.
PS: I see their puddle lights are tungsten. Are they easy to change if faulty?
I thought so, but I can deal with that. It should be a ladder resistor chain with a fixed voltage at the top. Voltage changes according to the switch position which their controller ADC measures requiring only 2 wires. I expect my basic door controllers will ignore the powerfold switch and I need to measure a switch to find out what voltages they are using. A couple of voltage comparators will do the trick.
The door mirror puddle lights use halogen bulbs that do put out a lot of heat and could deform the housings. You can either replace the puddle lights with canbus compatible LED housings or just replace the halogen bulbs with LED's. I opted for the later, just make sure if you do, you choose a LED bulb that has resistors so you don't end up with any bulb out lights. I replaced all of my halogen bulbs with LED's, that includes the two front driving lights, fog lights, four foot well lights, two map lights, glove box light, trunk light and license plate lights. Pure white and much brighter than the stock bulbs.