Trying to figure out which wires do what on the steering wheel shifter buttons. Experimenting is starting to get costly.There's a blue wire, a black wire, a brown-striped-brown wire (really?) and a brown-striped-red wire. I typically associate brown with ground on German cars, but since there's 2 brown wires, that's not the best indicator. Or maybe one of those is supposed to be some kind of German yellow...

Anyways, help would be appreciated. I already fried one of the switches by randomly jabbing 12v and ground wires around.

 

The colors change between the steering wheel and the clockspring.. what are you trying to accomplish? Have you tried using a multimeter to simply check impedance and then narrow down functions? I modded my tiptronic controls to be radio controls and I was able to figure out the purpose of each wire, etc. fairly easily with this method.

 

I'm trying to use the buttons for media controls with a dash-mounted tablet. But I have a manual trans car, so I don't have the wire harness past the clockspring. That means I can't test an existing setup. (I bought the steering wheel and airbag from eBay)

I'm trying to interface it with an aftermarket module that recognizes the button presses and converts them to keyboard input for the tablet (Joycon EXR). I figure if I split the wires up in the harness, that gives me 4 total buttons. But if I can't figure out which wire is supposed to do what, then I risk frying another switch.

I assume there is:

- a backlight wire (I think it's the blue one)
- a ground wire (not sure which of the brown ones)
- a + wire
- a signal wire which returns different voltage values depending on which button is pressed (each switch has a different resistance when pressed).

There's really only 3 possible values here: up, down or nothing pressed. Both sides should have the exact same resistance. But when I was hooked up to the Joycon EXR, all I could register was the up button and nothing pressed. Pressing the down button didn't work. So I assume I was hooked up to the wires incorrectly. When I attempted a different wiring scheme, I fried the up button on the left side. It went *poof* and all the magic smoke escaped, thereby rendering it useless.

 

I just did the radio control conversion a few weeks ago, if I remember correctly, one of the wires is for illumination (+12v), one is a shared ground, one is for up, and final wire is for down. That being said, this writeup may be able to help...

I do not remember the wire colors, and I'm actually curious as to how you're working around the clockspring harness issue. Did you convert that, as well?

 

Now I'm starting to understand, thanks to the diagram on that page. So these switches aren't resistive. They just ground either the br/yl or br/red wire depending on which button is being pressed. That's not at all how I thought these switches worked.

What's really odd is that I can't get the backlight (blue wire) to stay on steadily unless I ground the br/yl wire constantly. This is confusing, since the diagram implies that br/yl is a signal wire and black should be the ground.

On the other hand, that page helped me figure out how to get the switches working the way I need them to by adding resistors So thanks!

 

No problem! The issue with illumination is a little confusing to me, though. As long as the black wire is grounded (to the remote harness, on mine), and the blue has a stable +12v (to the radio remote-on wire, for amplifiers), it has worked with my steering wheel...

Also, have you swapped your clockspring, as well? I'm still a little confused as how you're getting that harness through the non-tiptronic one...

 

It's being connected to custom wires coming through the airbag/horn harness access hole, it's not connecting to any factory harness in the car. There's no need for a different clockspring. These wires can handle a couple of turns in them

 

Ah that makes sense - I'm now subscribed to your build thread, great pics btw!