[Akshay]

Hi there first post here so please go easy on me.

I purchased a new steering wheel for my car that has some buttons on it. My car doesn't have the hardware in order to make use of the OEM functions of the buttons but instead, I wanted to see if I could get the buttons to control something else so long as I can work out how the buttons work.

Can anyone tell me how I can test the fuction of the existing buttons so I can see if I can wire them up to something else in my car such as the handsfree phone unit?

The buttons also illuminate so I want to see which of the wires controls that so they can light up at night.

I will post up pictures of the wheel and writing in my next post.

 

[Akshay]

This is my new wheel:

This is a close up of the wiring from the buttons. There are 4 buttons in total, and each light up at night.

 

[Resqueline]

Not knowing about that design from before I'm afraid those pictures don't tell me much, but it would seem natural to me that it could incorporate a contact-less inductive transfer system though, in which case you'd need a similar coil (or whatever) mounted on the steering column (+ "advanced" electronics).

 

[Akshay]

Ok thanks I will try and get some more close up photos of the buttons and wiring when dismanlted further.

 

[Akshay]

Hi I have dismantled the button now and would like some help to work out what does what please. Is it possible for someone to tell me how it works and advise how I can modify it to wire up to a volume + and - button I have on a stereo remote? This button was originally a + and - button from the steering wheel shown earlier.

Front

Back

I've tested it with a multimeter and found that connecting either of the 1's and 4 together lights up the little SMD (LED) next to each button.

When connecting the meter (in diode mode) across pins 3 and 4 of each button the value on the meter goes from a fixed value to zero.

I don't know what pins 5 and 6 do on the plug. What I want is to get the LED's to light up at night (from a feed from the car which I will find), and utilise the buttons to work my stereo remote volume.

I already have a steering wheel remote that sticks on behind the wheel but want to feed the volume buttons on it from this button.

Anyone please?

 

[Resqueline]

That board looks easy enough to figure out, but what's at the other end of the wires?
Do you mean the LED's light up by themselves, or by the multimeter diode test?

 

[Akshay]

That board looks easy enough to figure out, but what's at the other end of the wires?
Do you mean the LED's light up by themselves, or by the multimeter diode test?

The other end of the 4 wires is a plug which goes into another box which contains a much more complicated looking PCB from which another plug goes to the car wiring. This plug only has 3 wires so 8 wires from 4 buttons ends up as 3. I guess this part won't be possible to use so I would just need help in connecting up to the 4 wires in each of the button arrays shown earlier (labelled diagram).

This is the main PCB showing the connections coming in from the buttons (L and R plug) and the output (centre plug)

With regards to the LED's yes they light up when connected to the multimeter in diode mode.

 

[Resqueline]

It seems to me the main PCB is connected to a 4-turn wire loop going around the hub, receiving power from it and communicating to the car via it too.
But if I understand you correct now you just want to connect the buttons to a remote that you're going to mount behind the wheel somehow (easy), but still get power to light the LED's (harder)? Sorry if I'm a little slow to catch up.
You will need to mount a similar wire loop in the column and drive it with some electronics to generate and transfer energy to the LED's.

 

[Akshay]

It seems to me the main PCB is connected to a 4-turn wire loop going around the hub, receiving power from it and communicating to the car via it too.
But if I understand you correct now you just want to connect the buttons to a remote that you're going to mount behind the wheel somehow (easy), but still get power to light the LED's (harder)? Sorry if I'm a little slow to catch up.
You will need to mount a similar wire loop in the column and drive it with some electronics to generate and transfer energy to the LED's.

Not sure how I'm going to get a wire from the car into the wheel though as the wheel will rotate aound 3.5 turns lock to lock so not sure how to wire it up in that respect.

On another note would the buttons in that picture be able to handle 12V? I'm thinking of using one of then as a push to close to activate an engine start button. The button would need to be able to send 12V to a relay.

 

[Resqueline]

You can't run wires directly to the wheel of course.
The original setup is a wireless/ inductive power & data transfer system, presumably comprising a 4-turn coil in the wheel and a similar coil in the column.
High frequency AC transfers power from the column to the wheel (just like in a transformer) and the wheel electronics transfers data back to the column the same way.
You'll have to replicate that somehow.

 

[Akshay]

You seem clued up on the car stuff. Yes it's called a slip ring to most people and they're quite expensive too which is now confirmed by your explanation. Looks like I'll find this little project challenging to complete. The best I can expect for then is just to hook up the buttons to my stereo's infra-red remote but not having the buttons illuminate is going to be a huge dissappointment .