AUDI A4 Wiring for Car Stereo

[SarahD]

I'm trying to fit a panasonic head unit into my 2004 A4 but I cannot find out which wire is the Ignition Switch. Does anybody know what colour it is?

[A4OBAN]

there isn't one. I found this out when fitting a head unit in my B6. The standard radio is switched on by a low voltage signal from the can bus.

Options are:

1 Connect the permanent live to the swiched live. Result means radio on all the time and flat batteries unless you remember to switch it off.

2 Spend around £20 on a 'can bus module' that will switch on and provide power when ignition key is inserted.

3 Tap into a fuse which is live when iginition on.

4 Or wire in a relay which is switched from the ignition loom (needs some, but not lots, of knowledge of auto eletrics and a circuit tester)

Also helps if you use the correct wiring harness adapator. I also found I needed an aerial amplifier to get a decent radio signal, even on FM.

hope this helps

[REZ]

there isn't one. I found this out when fitting a head unit in my B6. The standard radio is switched on by a low voltage signal from the can bus.

Options are:

1 Connect the permanent live to the swiched live. Result means radio on all the time and flat batteries unless you remember to switch it off.

2 Spend around £20 on a 'can bus module' that will switch on and provide power when ignition key is inserted.

3 Tap into a fuse which is live when iginition on.

4 Or wire in a relay which is switched from the ignition loom (needs some, but not lots, of knowledge of auto eletrics and a circuit tester)

Also helps if you use the correct wiring harness adapator. I also found I needed an aerial amplifier to get a decent radio signal, even on FM.

hope this helps

it really is a bloody nightmare fitting an aftermarket headunit! STILL havent got mine working fully.. do your rear speakers work as they did before with the new harness? mine are really quiet? leads me to think ive bought the wrong iso harness to power the pre-amped rear speakers..

[xenon]

I think there are two wiring adaptor available. One for 'BOSE' and one if you haven't.

[Mr_Meeks]

i just got a JVC KD-AVX44 fitted on saturday exellenct dvd head unit and look perfect in the Audi A4 04 yes you will def need a radio aeriel amplifyer and the sound should be even better through all the speakers once you've fitted a decent headunit. i have mine connected to live which just means i have to turn the headunit off instead of using the ignition, i dont think its a big problem personally, def not worth playing around with fuses etc......

good luck

[REZ]

I think there are two wiring adaptor available. One for 'BOSE' and one if you haven't.

youre absolutely right, i found out today i have the wrong adaptor!! correct one winging its way to me as we speak and hopefully be in for friday.. next job, replacing passenger side speaker..

[technohippy]

I have an 02 plate audi a4 b6 and ive replaced the head unit for an aftermarket model and have found that the radio reception is really poor.
i have used an aerial adapter (pc5-90) to supply a 12v feed to it as i needed to do on almost all of my other cars, but still the radio reception is very poor.
I noticed on removal that there is a yellow plug (pictured) that fits into the back of the old head unit (a concert cd unit) which i havent used in the new one as there is no space for it, does anyone know what this wire is and what relevance (if any) it has to the poor reception.

[fifer1981]

there isn't one. I found this out when fitting a head unit in my B6. The standard radio is switched on by a low voltage signal from the can bus.

Options are:

1 Connect the permanent live to the swiched live. Result means radio on all the time and flat batteries unless you remember to switch it off.

2 Spend around £20 on a 'can bus module' that will switch on and provide power when ignition key is inserted.

3 Tap into a fuse which is live when iginition on.

4 Or wire in a relay which is switched from the ignition loom (needs some, but not lots, of knowledge of auto eletrics and a circuit tester)

Also helps if you use the correct wiring harness adapator. I also found I needed an aerial amplifier to get a decent radio signal, even on FM.

hope this helps

any idea where i can get one of these modules ? or any way of making some thing that feeds off the permenant live thats non active untill the can wire wire power switches it to connect the permanent live

or is the item at the bottom any good ? http://www.nexxia.co.uk/Car_Stereo_fitting_kits.htm

[Beaversport10]

I believe the yellow wire is to do with the speed sensitive volume adjustment on the Concert cd head unit.

[DBSK]

Does anyone know what the power of the amplifier is in a 2004 A4 Avant? Its got a small sub in the side of the boot and i want to upgrade it if possible.

Is it possible to:

Wire a slightly bigger sub (depending on size of the Audi Amp) instead of the Audi sub?

Or

Remove the wiring from the Audi Amp, install a new bigger amp and then a bigger sub?

I want to keep the standard head unit if possible which i didnt think was going to be possible until i saw it already has a small sub from factory.

Ta.