DIY – Radio control on steering wheel
 

First thanks to Rennlister 'David in LA' for the steering wheel.

This was real simple and you can use any radio that has an IR remote.

SWI-X Steering Wheel Radio Control Interface (converts button pulse to IR signal):
You only need to hookup 3 wires and the IR emitter.
- Red wire goes to 12volts ignition (I used the wire which was already there for the radar detector)
- Black wire goes to ground
- White wire goes to the buttons
- The IR emitter just plugs into the unit and is mounted near the radio (mine is mounted above the radio, where the rear fog light switch goes on European models).

Next modify the tiptronic buttons:
- There are 4 wires that get married to 2. All I did is cut into 3 of them and solder resisters in line. 1st wire 500 ohm, 2nd 1000 ohm, 3rd 1500 ohm (the value of the resisters does not matter) 4th wire no resister goes to ground.
- Take your multi meter and measure the resistance to ground; when you push up on a button there should be a short to ground, when you push down on the same button it should read 500 ohm. On the other button push up and you should get 1000 ohm resistance and last push down on that button and get 1500 ohms (or what ever resistive values were used).
- Connect the two wires from the tipronic wire harness to the white wire of the SWI-X.

Program the SWI-X:
Basically you will push one side of the tiptronic button, then push the IF command on the stereo remote to train the SWI-X. Do the same for the other three and your done. The manual explains it pretty well.

That’s it. I programmed my right buttons to control the volume and the left to change stations, up and down. It works great.

Here are some picture of the SWI-X and the emitter, let me know what you think.

Sonny