A8 - 4.2L

Looking for a diagram of where the optical bus is routed throughout the vehicle.

Hoping someone with a decent set of manuals can help please?

PaulW

I might....what do you need it for?

PaulW

<i>Hello Paul,

Thanks for the reply. A couple of us have the Bluetooth MOST boxes and are attempting to retrofit our onstar equipped A8's. The dilemma has been trying to find the closest and/or most convenient connection to the MOST bus near the driver seat. Without having to tear the car apart, a diagram of where the MOST harness is routed on the 05's would be fantastic.

Only point we know of right now would be the glove box area, but it's quite a pain to route the connection from there all the way to the driver seat...
(unless you know of an easy trick) The other is the trunk area - but there's gotta to be something closer!

Eagerly hoping you have a diagram. I've studied your installs in the past and they have been the most detailed I've been able to find on this topic anywhere!

Hoping you can help.

Regards,

A8 - 4.2L</i>

Answer:

If you are looking to put the module under the driver's seat where the telematics module is, then you could go to the CD changer, that would be easiest. But you will still have to route a few items that are probably not there such as the "line/ring break up diagnostic system" but that's probably it. All other needed connections would be at the telematics module.

Or the other option would be to make a custom plug and play wiring harness and route it from the telematics module (unpluged, plug in your new harness) and run that harness to the trunk. If that was the case, see my first answer below, but then realized that everything is already at the telematics module that you will need.


------------here were my first thoughts-------

If you are putting in a factory MOST bluetooth module, I would put it in the trunk for a couple of reasons:

1. So easy to get to.

2. You can add the component to the MOST bus right at the Sateillite radio/nav connections.

3. You'll have all the necessary power, ground, K line and MOST bus troubleshooting wires right there for the other components, you just need to jump off them or see if the AMI wiring harness would work for you. I have not seen one, but I know it just piggy backs the CD electrical connector in the glovebox....so it's plug and play.

I would figure out the connector numbers you need/have and make a plug and play wiring harness, it would only need 3 or 4 wires, use the Audi connectors.

If you have any concern about it not working because it's in the trunk, there will be no problem. That's where my bluetooth module is hooked up.

I emailed you the wiring diagrams.