Blizz

2004 A6 with 4.2l. Bose Symphony II.

Can't get a damn radio signal. I can get maybe one local station if I'm parked in the right spot, but as soon as I move, I feel like I'm in Auschwitz.

Anyways. VagCom says radio amp is grounding out. I cleaned the rear window as someone else suggested to no avail. The antenna is plugged into the back of the radio.

So my question is where the hell is this amp located so I can replace it.

eejimm

Actually there are several in the D-pillar (behind the rear seats), two on each side (depending on specific options) plus one in the trunk to select which one is being used (the diversity selector). That's if you have the antennas on the rear window.
If you have a motorized telescoping antenna (I've yet to see one, but the wiring diagrams say it exists) then there are only two amplifiers.
Before you take the car apart, I'd check to see if the common ground for all of then has come unhooked. Also, they are powered through the two (yes there's one for AM and one for FM) coax cables from the head unit. so double check to be sure they are connected. It's hard to believe that they all would go out at once, so I'd suspect some common element, like one of the connectors or possibly the diversity module.
Jim

Blizz

Thanks for the response Jim. I did a quick look-over in the trunk and I didn't see any modules that looked foreign. Can you be a little more specific of the location of the diversity module and common ground?

My car has sat-nav and sat-radio, if that helps determine the ammount of boosters I have. It's a sedan. No exposed antenna. Pretty sure it's in the rear glass. The shark fin is xm only right? That works fine.

johnkk

To access the amps, you have to drop the C/D pillar trim(for you on both sides). Check the wiring harnesses for crimped/bare wiring.

Boston Driver

Here is a picture of the antenna amp in my A6 4.2 located under the D-pillar trim as eejimm mentioned (ignore the red circles in the picture, those are reference for something else). To remove the D-pillar, see my AW tech writeup:


You should also check the solder points (you can barely make them out in this pic) which is a weak spot in the diversity antenna since so much moisture builds up on the windows.

Blizz

Thanks for the pictures and info!

shweb

I've been poking around and STF on this. I have all but lost AM reception. Intermittent and worsening by the day. I have '03 A6 with Symphany II and pulling the "00858 - Connection; Radio ZF Output to Antenna Amplifier 44-00 - Short Circuit" code. The Bentley manual shows 4 separate antenna amps, all behind D-Pillar trim, both sides, and the selector module "underneath left side parcel shelf", although I've seen on the forums where the selector module is above the rear of the headliner, in front of the top of the rear windshield (?). However, the Bentley manual also shows a separte CD changer in the trunk, which is not the case, as it's in the HU.

My questions:
- How would one determine which amp might be the culprit, or if it's the diversity selector module?
- Do the VAG codes indicate which amp? The Ross-Tec website doesn't mention anything about that, just to "Check Wiring/Connectors from/to Antenna Amplifier". Which side? Which amp? Any good way to take an educated guess?

I have an RNS-E in a box that was intended to replace the factory Symphany II quite a while back. Am looking to FINALLY get around to installing the RNS-E, but figured I'd want to correct this first.

zoomzoommp5

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