2003 Audi A3 - Stero / Head Unit Wiring Issues

jordann

jordann

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Hello All,

I've got a 2003 Audi A3 (2.0 TDI) and i've recently changed the head unit to a new pioneer app radio (double din) and i've got a few wiring issue's.

I'm no mechanic so you'll to excuse me if I get thing's wrong or mixed up but i'm told that because I had no switch live wire we had to wire one directly from the fuse box, I believe this is because the standard double din disc changer and radio use a canbus wiring system where as the new one can't or doesn't use it or whatever.

Basically i've now got a yellow wire running from the fuse box to the block wiring kit, then it goes into the back of the unit. At the moment we're running of the sunroof fuse (My car doesn't have a sunroof), but the only issue that it requires two clicks on the ignition to work where as i'd like it to work on the one, so I don't have air con and other pumps running. I'd also like it to stay on if I turn the car off... UNTIL I pull out the key, very much like the standard head unit. Basically i'd like it to work just like the old one, bar the fact the old one didn't require the key switched to the first position to work.

Could anyone recommend a different fuse port to use or something else that can be done?

I'd appreciate any advice or help.

Thank you.
 
I would love to know if there's a can bus cable that replicates the "accessory" function precisely. The connects2 canbus adapter I have doesn't - it uses voltage sensing. "ignition" stays on for a random time after you switch off, but it's not related to when you remove the key
 
To answer the OP - there is no "accesory live" feed in the fusebox, only ign live and batt live
 
JohnE said:
To answer the OP - there is no "accesory live" feed in the fusebox, only ign live and batt live
Click to expand...

Ta for your help John.

Are you saying that there isn't any fuse within the box that would work as I want it to? I'd have to wire it directly from the ignition switch?
 
The Canbus adapter in those links looks just like the one I've got - and mine doesn't emulate accessory position, it just senses voltage drop. They may have updated it of course.
 
goodingj said:
Ta for your help John.

Are you saying that there isn't any fuse within the box that would work as I want it to? I'd have to wire it directly from the ignition switch?
Click to expand...
Er - rather late in the day, yes I am saying that. In fact, because the ignition switch wire only feeds a tiny signal to the canbus unit, wiring a radio to supply to that may overload it, so I don't think that's an option.
 
The appradio has been wired directly from the fuse box for quite some time now and all appears to be okay, however it's just a shame it doesn't work as the old one did, I used to like the fact it stayed on after I killed the engine and did so until I took the key out. I just wish that I did more research on the unit itself before purchase, but I suppose that you can't really get the feel of it until you've used it for a while in your own car.
 
Using the canbus adapter was even more weird - when you kill the engine the radio does indeed stay on a while - but it's a random time, and it doesn't go straight off when you take the key out either - I guess it's due to some kind of Hysteresis built into the voltage sensing so that it's not constantly switching on and off. It's a shame they couldn't make the adapter read the actual canbus signals like it does for the other stuff.
 
It is a shame yeah. The problem is that the majority of my driving is local and so I have to keep an eye on my battery level. I know that once you turn over the car you're meant to put approx 7 miles into the car to recharge what you've just used. I normally just drive to work, gym and local friends, none of which are over 7 miles (I should probably cycle more - I blame British weather). I'd like to be able to sit there and listen to the stereo once I've turned the engine without having to turn the key off and back on again, starting all the pumps up. Just seems like a pointless waste of electricity. Well, if I want to continue to be picky I should probably chuck the old one back in :( I'll see how I get on. Cheers
 
What about just ignoring the CANBUS and connect directly to the power? I've not installed the CANBUS adapter at the moment so have it all wired up permanently, I remove the facia of my headunit which keeps the unit off (apart from power to the HU's clock). I've not had any flat batteries or power issues yet, and it means the headunit stays on after the engine/ignition is off.
 
benjibarnicals said:
What about just ignoring the CANBUS and connect directly to the power? I've not installed the CANBUS adapter at the moment so have it all wired up permanently, I remove the facia of my headunit which keeps the unit off (apart from power to the HU's clock). I've not had any flat batteries or power issues yet, and it means the headunit stays on after the engine/ignition is off.
Click to expand...

My AppRadio doesn't have a facia, it's a solid unit. It doesn't even have an off function. Wiring up to the fuse box and using the adapter is the only way. Cheers anyway
 
How brave do you feel about getting into the factory wiring? You could check the key cylinder to see if there is a keysense wire- radio would stay on until you physically remove the key. Definitely use a relay here, should be a low current wire. Alternately, if you can find the door trigger wire you could again use a relay and keep the radio on until a door is opened. Another possible option is to connect a relay to the dome light to keep the radio on while the light is on, normally the light turns off after you exit and lock the car or after a few minutes of inactivity. With any of these methods, you should diode-isolate the new switched wire from the existing one in your harness and keep the wire in the harness connected too.

Easiest way though would be to use a CAN bus harness. If the Connects2 isn't working to your satisfaction, you could try PAC or Metra (assuming that they are sold on your side of the pond.)
 
On a scale of 1-10, i'd say about minus 10. I appreciate the advice though. I'll just have to live with it for now :D
 
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