Speed signal wire?

[GeneralWest]

I brought a heads up display unit today that projects a speed readout onto the windscreen. It works in KM and I'm off to Le Mans in a couple of weeks so I thought I'd wire it up for the journey. It needs a speed signal input to make it work.

Can anyone suggest an easy place to pick up a speed signal from inside the car? Preferably without having to take lots of interior trim apart.

 

[Broken Byzan]

behind the dash pod, white / blue. Or even from behind the stereo, IIRC there is a gala signal there

 

[GeneralWest]

Nice one, thank you. I'll check behind the stereo first. What exactly do you mean by the dash pod?

 

[16Klappe]

Nice one, thank you. I'll check behind the stereo first. What exactly do you mean by the dash pod?

The dials themselves :icon_thumright:

 

[jojo]

Isn't it more difficult to extract the speed pulse from the wires if the car has canbus wiring?

 

[GeneralWest]

The dials themselves :icon_thumright:

That's what I was afraid of. I really don't fancy taking the dash apart. I think I remember seeing a gala wire somewhere behind the stereo on my old pre-facelift S3 but I could be wrong. You can use the aircon display to bring up current road speed so maybe I can find something there.

 

[GeneralWest]

Isn't it more difficult to extract the speed pulse from the wires if the car has canbus wiring?

You might be right. I don't really understand how the canbus system works.

 

[jojo]

You might be right. I don't really understand how the canbus system works.

Off the top of my head, you need some kind of adaptor/lead that goes inline with the wiring loom. Not sure from what year the canbus was installed into 8L S3's, but I'm sure later models are.

 

[S3 Nattie]

Ive taken 2 speed signal for my navi, 1 behind the instrument cluster and the other from some wires in the passenger footwell. I cant really remember the pin numbers but thats were I got my 2 speed signals

 

[GeneralWest]

For anyone who's interested I managed to find out that my car doesn't have canbus. The speed signal wire was in the main power connection block for the stereo. It was a green/white coloured wire that was in line with the permanent live on the opposite side of the plug. The HUD is now installed and working.

 

[s3dave]

For anyone who's interested I managed to find out that my car doesn't have canbus. The speed signal wire was in the main power connection block for the stereo. It was a green/white coloured wire that was in line with the permanent live on the opposite side of the plug. The HUD is now installed and working.

:sign_pics: