Notes on alternative (easier) retrofitting of phone prep in glove compartment Audi A6 (4F/C6)1.6.2008 - Note: This article covers my notes on a potential retrofit project that I have not performed myself, so I can not say if my notes are fully accurate or not. However, I think this may be a good starting point for someone interested in this type of project. I have mainly researched A6, but much of this is likely relevant with Q7/A8 too.
If you read my report on retrofitting Bluetooth phone prep on an A6 on this site (go to the index and look there), you will see that I have done it the hard way - the right way, to be exact, by placing the telephone module beneath the driver's seat where it would be installed at the factory as well. This process left me wondering if there would be an easier way and I think there is.
Many people who have retrofitted the phone prep on pre-MMI cars (like last generation A4), see e.g. navplus.us forums, have apparently installed the telephone module behind the glove compartment. This is understandable because it is easier to access and with pre-MMI the connection point (radio) is also nearby in the center console.
Things are a bit different with the A6 MMI phone prep installation, mostly because there is a MOST fiber-optic cable that goes from the main or front MMI unit behind the glove compartment to the CD changer there to the telephone module under the driver's seat and then from there to the amplifier in the component rack in the left side of the trunk. The Kufatec.de retrofit kit includes a long MOST cable that is used to replace the existing MOST cable in the car that goes from the CD changer to the amplifier with one that goes from the CD changer to the phone module first and then on to the amplifier - because the telephone module must be (well, is supposed to be anyway) in the MOST loop between the CD changer and the amplifier.
However, there already is a MOST fiber-optic connection existing between the glove compartment area and the amplifier in the trunk, this is the optical cable going to the CD changer in the glove compartment. If the telephone module were to be installed behind the glove compartment, surely one could just connect this cable to the telephone unit and run a new, short cable from the telephone unit to the CD changer unit in the glove compartment and thus retain the integrity of the MOST loop without meddling under the driver's seat? I haven't tried it, but the logic would seem to work. I think it would work. You might need a shorter MOST cable, maybe a navigation cable kit from Kufatec would be useful or a second CD changer cable kit. No need to route a cable from front to back or mess around under the driver's seat!
This would also help with a few other things, there is this small green cable that must be routed from the telephone module under the driver's seat (in addition to the MOST cable) to the CD changer in the glove compartment and soldered in one of the pins there. If the telephone module were to be installed inside the glove compartment, this cable connection would be shorter and easier too - perhaps even that navigator cable kit could help here and spare soldering directory to the CD changer's cable - the navigator cable kit includes some adapters that allow easier connection to these kinds of cables (the navigation retrofit kit is much more plug and play than the Bluetooth kit is requiring no soldering).
Only few issues would remain. One of course is power, because the telephone units fuse spot is in the left side of the car. However, I'm sure there is a similar free spot in the fuse box in the right side of the car - and there certainly is ground connection there too. Second issue is that the microphone would have to be routed from the right A pillar (instead of the left) to the roof, but I see no problem in this - it is just doing the same thing on the other side of the car. Third issue is where to physically attach the telephone module (which would have to removed from its plastic box) because there is no natural place for it behind the glove compartment. I think it could be easily fitted under the main/front unit with velcro or some other type of attachment since people have fitted Densions or other modules there too.
Fourth and last issue I can think of is the only one I would be somewhat worried about, but not much really. The Bluetooth antenna is in the telephone module and instead of being near the driver (and the phone usually), it would now be behind the glove box (and possibly behind the electronics of CD changer, maybe AMI in the glove compartment too). Is there any interference there that might bother it? Probably not, since the Bluetooth connection works just fine outside of the car as well when installed in the factory location. Also, many people have used this spot for the installation in pre-MMI cars (see above), which would suggest it works - however, those cars have less electronics in the glove compartment area, so less interference...
In any case, this should in no way affect installation of the speech dialogue system module inside the radio in the left side of the trunk, since that is a wholly separate matter (although requires that the telephone module is installed in the car because the microphone connection goes through the telephone module) and simply plugs inside the radio.
Feel free to let me know if anyone tries this, how did it work out!
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