# Replacing 2004 Audi TT Headunit with Bose...Please help!



## Fuzion15 (Feb 19, 2011)

Hi everyone,

I am obviously new to this site and I found it when I was searching for ways to replace my head unit with the factory Bose system in my 2004 Audi TT. I found a thread that talked about it with pictures, but there was no real info other than "use the crutchfield harness." 

So, I have everything I need from crutchfield and hooked everything up with the default harness configuration, but the radio does not come on when I plug everything in. 

Now, I have read reports of having to run a power wire to a fuse, which is confusing to me to find it. I have also read reports that the harness should just work. I am almost tmepted to purchase the C2R-Audi kit like people are saying, but it almost looks like more of the same just with a control box. 

I would appreciate all input possible.

Thank you


----------



## aTTlas (Feb 26, 2010)

I ordered my new head unit from Crutchfield, and it was pretty straightforward. There's the wire harness that plugs into the Audi plugs, and the wire harness for your new unit. Solder the corresponding leads together, and it's plug-n-play. If something isn't coming on, I'd re-test your connections. I'll be pulling mine apart later today to splice in another circuit if you need to see what I mean.


----------



## Fuzion15 (Feb 19, 2011)

Well, I looked at the wiring harness and the pins seem to not match up with the audi system.


----------



## aTTlas (Feb 26, 2010)

I think I may have misread your original post...are you trying to replace a standard HU with a Bose unit, or the Bose HU with an aftermarket setup?


----------



## Fuzion15 (Feb 19, 2011)

I am replacing the Bose HU with an aftermarket HU. 

Thank you. You didn't happen to take pics when you were in yours did you? lol.


----------



## TTRU (Mar 5, 2006)

I know you need two connections for switched and constant power. That screwed me up too - this might help, quite a few links in there.

GL!

http://forums.audiworld.com/showthread.php?p=16967250


----------



## Fuzion15 (Feb 19, 2011)

Thank you for the link. Can you tell me what you did with the switched/constant?


----------



## Doooglasss (Aug 28, 2009)

I believe the issue is that the CANBUS TT's only had constant power going to their stereo's. When hooking up an aftermarket stereo you need an ignition power source as well.

Power sources can be found under the drivers side dash. Use the very beginning of this DIY to learn how to remove the dash.

http://forums.vwvortex.com/showthread.php?4782217

I can be wrong as well so go over your connections and see what wire you're missing. If it's constant or switched. Either way both of those connections can be found under the dash. Use a multimeter. I'd strongly recommend an inline fuse setup unless your stereo has a fuse on the back of it.


----------



## Fuzion15 (Feb 19, 2011)

That is where I am getting confused. Some people are doing it without running the additional cable. I see a lot of people saying that the wire harness is just fine. I am confused about it lol.


----------



## poopie (Feb 22, 2005)

it depends on the year. Early model TT's were no can-bus and the adapter harness would be fine. Just run 2 addition lines from under the knee bolster. The easiest place to grab the ACC on power is from the VAG-com connector harness.


----------



## Doooglasss (Aug 28, 2009)

I would not hack into the OBD port connection when you can just unscrew a 10mm bolt right next to it and slide the wire in. There are both always on and ignition power on those terminals. 

Pre 2003 TT's were KEYCOM and could use a direct plug and play harness without additional wires.


----------



## Fuzion15 (Feb 19, 2011)

Ok so I am assuming the 04 model is a CANBUS...what about the C2R-Audi by PAC...does that eliminate the need and make it worth the extra $100 instead of running the wire to the fuses?

I appreciate everyone who has chimed in so far.


----------

