Aftermarket Headunit Wiring - Bose

Arkious

Registered User
Hi All,

I have just fitted a new Android head unit to my RS3 and it works pretty well out the box. It came with all the wiring adapters so that the steering controls etc. all worked straight away. I have a few things I am hoping someone might be able to shed some light on however as I am a complete novice when it comes to this.

Bose - the speakers all work but there is a buzzing/ humming that gets worse when the engine is on. I remember a similar thing happening when I retrofitted the RNS-E into my old A3 and the Bose pin needed activating. However I cant seem to find how to activate the pin as nothing goes to it at the moment.

switched live/ permanent live (ACC?) - Is this what I need to wire to so that the head unit will boot when the car is unlocked like the audi head unit did?

Radio Antenna Amplifier - This needs powered, so do I power it with the same wire as per above?

Thanks very much for any help!
 

Arkious

Registered User
Anyone?

I have ordered two Ground Loop Isolators to try and fix the audio issues, that’s all I have managed so far!
 

tcg

Registered User
Hi mate,

Stumbled across this thread...from the A3 8L group.With the Bose question,I seem to remember reading online that the
Bose pin needs to be 'grounded',does that make any sense to you...you may need to do some more googling.

As for a switched live,when I need one I checked out the fuse panel diagram and found a spare one that I could use for my aftermarket bluetooth.My fuse box is on the driver's side of the dash,behind a panel...

https://www.audi-sport.net/xf/threa...ad-my-baby-is-home.261997/page-3#post-2766711

Obviously depends where your fusebox is located.

HTH
 

Arkious

Registered User
Hi pal,

Thanks for for that, I have just tried grounding the pin but unfortunately it had no benefit :/

The two ground loop isolators I have have ordered should arrive today, on top of that I also have a coil to fit on the 12V input to separate the live, apparently that was a thing on older cars?
 

tcg

Registered User
Hi mate,

I'm 54 so can remember noise suppression on radios...usually an in-line one on the power supply and one on the alternator if the sound increased with revs.

Might be best to find a switched live for the stereo first as that might reduce the noise by separating the power feeds...at least you'd have a starting point.

Not much help I'm afraid,but always helps to bump up a thread.
 

Arkious

Registered User
Ahh well that’s good to know, I have one here but it turns out having the two ground loop isolators has rectified the problem :) so sound is much better now, not perfect but that could be down to fine tuning or I now may need to ground the Bose pin!

I’m hoping to use the OEM microphone, I can just piggy back off the + and - mic connections?
 

tcg

Registered User
Mic should work fine I think mate,it's just a case of two wires +/-

Just need to be the right way round and I think after what you've done,you'll soon have that sorted :yes:
 

JohnS3

Registered User
The Bose pin is grounded if Bose is factory fitted. This just turns on a flatter EQ curve in the head unit (that is no longer connected) which could be the reason you don’t hear any difference. :)

The Audi head units are “live” and are turned on and off via CAN signals. The live feed should have been taken care of with the conversion loom supplied with the Android unit?

Now to the antenna. Depending on the year of your car and what was fitted radio/RNSe this will determine the antenna configuration in the rear screen. If I recall correctly (I have a long thread on here about converting antenna systems, written many many years ago!) post 2007 MY cars with non RNSe head units have 2 separate antenna systems in the rear screen, this is phase diversity. The head unit then switches to the one with the strongest signal. The RNSe and pre 2007 cars have a similar 2 antenna system only this time there is 1 antenna feed to the head unit and 1 return feed back to the rear antenna amplifier so it can switch to the strongest signal, this is switched diversity. This return feed is known as the ZF feed. so be careful when you are choosing the antenna connection for the android. You may need a diversity double Fakra to DIN adaptor cable to restore the antenna switching if your car is post 2007 with no factory RNSe.

I know, I should get out more...
 

kritter86

Registered User
Sorry to hijack the thread. Just got an aftermarket Sony head unit and wanted to know how to keep the OEM microphone?

Out of interest @Arkious do you have a USB port coming out of your head unit? Where are routing the cable? through the glovebox or out of the fron of the dash somewhere? I thought about one of the unused buttons next to the hazard switch but I dont think it'll fit.

What are you doing about a DAB signal input as well?
 

Arkious

Registered User
Thanks for all the replies guys!

@JohnS3, I have done exactly that and used a double fakra to DIN converter for the radio tuner, it’s still not the best tuner in the world so might see if I can solder in a UK one rather than a China one. Again I bought a Fakra to DIN converter for the GPS antenna and that’s working perfectly.

I have a few things to try with regards to getting the OEM mic working today so I will let yous know how I get on with that, I’m hoping the wires I need are already there!

As for the USB ports, yes I have 2 coming from the unit but I haven’t wired them to anywhere specific yet. To be honest the unit is just in its test fitting phase as I want to ensure I can get everything working before I commit. I’m replacing a 193G RNS-E which works perfectly, so I need to have this working perfectly also.
 

JohnS3

Registered User
You need more than a double Fakra to din converter. It needs to have some inline electronics to restore the diversity function. Give connects 2 a call and they will advise the correct one.
 

Arkious

Registered User
Ahh ok thanks pal al take a look at it!

managed to reroute the cables to use the OEM mic but I need to make up an adapter yet to test it
 

Arkious

Registered User
There was spare cables that I could adapt to use the microphone, but so far even though it’s plugged in it doesn’t seem to work. Not spent much time on it yet
 

JayTeeA38P

Registered User
@Arkious how have you rerouted the cables to use the OEM mic? TIA.

I didn't have an OEM mic installed, but bought a standard 3.5mm jack one from Amazon. It's in the OEM place, in the map light cluster, and the cable goes across the roof inside the headliner, down the left-hand-side A-pillar (RHD car), behind the glovebox, and into the radio.
 

Arkious

Registered User
I didn't have an OEM mic installed, but bought a standard 3.5mm jack one from Amazon. It's in the OEM place, in the map light cluster, and the cable goes across the roof inside the headliner, down the left-hand-side A-pillar (RHD car), behind the glovebox, and into the radio.

That is what I wanted to avoid with the OEM one being there already. I am going to bell the cables to check that I have indeed tagged onto the correct cables.

I am wondering if the mic goes to the Bluetooth prep before going to the RNS-E?
 

JayTeeA38P

Registered User
That is what I wanted to avoid with the OEM one being there already. I am going to bell the cables to check that I have indeed tagged onto the correct cables.

I am wondering if the mic goes to the Bluetooth prep before going to the RNS-E?

I don't know about the "bluetooth prep" as I don't have it, but it's not too tricky to route your own cables. If you pull down gently on the front of the headliner there is room to manoeuvre things. The A-pillar trim pops right off. The plastic panel to access behind the glovebox pops right off. Then use a straightened wire clothes hanger to poke through to the stereo "hole"!
 
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