when i bought my car it already had a aftermarket cd player installed. the radio reception has always been complete *** and i decided to fix this. i got a powered antenna adaptor with the built-in signal booster and attached to the factory antenna wire and plugged into my aftermarket deck. it helped a little bit, but reception still pretty much sucks. my question is this....the factory antenna also has another black wire that is ran in the wiring bundle with it but it is not plugged into anything. what is this wire? is it just a ground for the factory antenna signal booster? or is it the factory signal booster input itself? where do i need to plug this wire into?

 

What does the black wire look like? Does it have a round end? If its a single black wire with a round end thats your FM antenna wire which goes to the back of the car to the diversity controller and fm antenna.

 

it looks like a basic black wire...about 16 gauge or so. i dont know what the original connector looked like cause the previous owner of the car cut off the end and put a basic terminal lug on it and connected it as a ground inside the center console. i disconnected it and the reception actually got a little better with it disconnected so i'm pretty sure its not supposed to be a ground. i just dont know what it is supposed to be. and my reception still sucks *** and i have the powered antenna adaptor that everyone said is the only thing i should need. if it is the FM antenna wire like your saying, then i need to splice it into the antenna input wire for the aftermarket stereo? any help would be great.

 

wait...when you say "the wire with the round end" i think your talking about the regular antenna...thats not what i'm talking about. i know what that is, and i have the powered adaptor that you need for aftermarket decks. i'm talking about the only other wire that is ran in the wiring bundle with that antenna wire. they both go to some connector on the drivers side in the trunk, behind the trunk liner, underneath where the oem "toolbox" and jack ar located...i have no idea what that other wire is

 

The only factory antenna wires are the black one with the round end (FM) and the white wire by itself (AM)
All the other wires are for speakers, 6 cd changer, bose amp etc.
Im not familiar with this powered adaptor but if your not spliced into the antenna wire then your not gonna get a signal. Those wires you are seeing in the trunk are for the 6 cd changer and the other one that looks like a printer port isn't used in the US.

 

i havent seen any white wires anywhere. for some reason it says i am not allowed to post attachments or i would put a pic of what i'm talking about. my car doesnt have the bose system or a 6 disc changer so it shouldnt be any of those either. this black wire that i'm talking about is literally taped together with the round FM antenna wire, all the way from the trunk to the back of the factory stereo. somebody has to know what this wire is for...

 

Those are for the 6 cd changer, every damn audi is pre-wired for navigation, etc. Just because you don't have a 6 cd changer doesn't mean the wiring for it isn't in there. ALL A4's have that wiring, i know exactly what your talking about.

 

ahh ok, thanks for clearing that up. but so then why do i still have such horrible FM reception and absoultely no AM reception? i have the powered antenna adapter from scoche that everyone said i needed to buy and everyone else said that it solved their problems but my reception still sucks. what wire should i be splicing into for the power antenna adaptor?

 

Because your not spliced into the right wire! You won't even need an adapter if you hit the correct wire, its the wire i already told you about. If you want to find the antenna and diversity controller directly, take off the D pillar on the driver's side (the back pillar) and the diversity controller will be sitting right behind it. The AM and FM antenna wires go directly to it.