Antenna is nonfunctional?? [Archive] - Audi Forums

: Antenna is nonfunctional??


Boy Scout
11-08-2011, 04:21 PM
I tried the search 3 times and it kept crashing ...

CD player works fine ... just the Radio is out ...


so, first question is: where is the antenna for my car?
(* as crazy as that sounds *)

I did not look for a fuse since it does not go up and down like the old mast units.


I did hear from one friend that sometimes the radio fails to use the antenna and a dealer is needed to repair the radio ... I hope that this is not the case.

Help appreciated.

mullardel34
11-10-2011, 09:58 AM
Boy Scout,

The radio antenna in the 2004 S4 Cabriolet is hidden on the underside of the trunk lid (bet you didn't look for it there, did you? I certainly wouldn't have looked there... ;-)

A number of owners have found that the bend in the antenna under the trunk lid stresses the center conductor of the plastic-sheathed antenna, prompting breaks in the center conductor near the bends of the antenna; this is the root problem. You can either buy a replacement antenna from an Audi dealer (I haven't seen this part carried by any third-party suppliers), or you can feel along the sheathed antenna to locate the break, slice through the plastic sheathing, repair/solder the center conductor and seal it back up.

Be aware that there's an antenna signal booster in the wiring between the antenna and the in-dash head-unit; the antenna signal booster is powered by 12V DC voltage provided at the antenna jack on the rear of the in-dash head-unit (you should be able to measure 12VDC between the center conductor of the antenna jack and the outer shield/ground of the coaxial jack).

Good luck! :cool:

Boy Scout
11-10-2011, 10:18 AM
thanks ... I will crawl into the trunk this weekend.


this makes total sense ... last time radio worked was on the way to golfing, when I went to leave afetr having forced the clubs back into the trunk no more radio ...

mullardel34
11-10-2011, 10:32 AM
It sounds like you're on the right track. The antenna center conductor may have already been flexed to the breaking-point by prior opening/closings of the trunk lid; that last bump as the trunk was closed during your golf outing may have been "the straw that broke the camel's back", so to speak. Just an unfortunate coincidence... :)

With all of the current bread-crumbs pointing at a busted antenna mast, it's unlikely that the signal-booster/amplifier has also failed; so, you most likely just need to repair or replace the antenna mast (it's about $100-$150 at the Audi stealership, from what I understand).

Just make certain that the internal emergency-trunk-release handle is operational before climbing-in for a look around... :cool:

Boy Scout
11-14-2011, 08:39 AM
so, the problem is a broken antenna wire

the break is somewhere in the loop that is in the water drip tray area of the trunk lid

so, I went with the McGyver solution ... I taped 1/2 of a pencil to keep that part of the flexible wire harness straight and now the radio functions perfectly

I will have to replace the antenna wire at some point ... just not today.

mullardel34
11-14-2011, 12:44 PM
Excellent! So, you've located the problem and already applied some in-the-field triage protocols to correct the problem until you have time to determine how you want to permanently repair the antenna. Nice. :cool: