Advice on Headunit Wiring (Manually) - HU to keep memory

Brooksy

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I have a Pioneer Headunit, relatively new and upmarket than cheaper ones. Been in the motor ever since bought the car. When i wire the headunit up correctly it will keep memory happy days.. but my remote central locking won't work. I.e I'll have to use my key in the door to open all doors etc. If I take the memory wire out (disconnect) the car's remote central locking will worbut I won't have any memory on the headunit.

I had a JVC headunit plugged in 6months ago for abit until it randomly blew. And when that was wired correctly everything worked all fine. Now.. It's got to the stage where I want my Pioneer to keep it's memory but obviously I want to keep my remote central locking.

Does anyone know what the issue is at all, or is there another wire on the adapter I can split and use for memory aswell to try out.

I don't want to go and buy a new headunit when this works perfectly fine. just need the memory to work.
SO then i can then go on to installing subs and an amp if I chose to.

thanks

For note:

I have a 2000 Plate Audi A3 8L
 
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Can you post a pic of the wiring at the back of the HU. Sounds like someone has rewired something incorrectly as this should not have anything to do with the central locking. A 2000 model A3 would not have an ignition on feed at the HU as they switched to CANBUS, so maybe someone has rewired it incorrectly to give the HU a switched positive.
 
b2231eff.jpg


Here's a pic of my wires setup. Currently the wires aren't switched. But tell mr which ones and I'll try again.
If you need more pics or of a certain area just let me know.
Thanks
 
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Need to see what is going on in the arrowed sections below as the yellow wire at the top of the picture is not original so looks like someone has butchered something:
AudiHUwiring1.jpg
 
Just noticed you are in Southampton, more than welcome to drop round to mine and I'll sort it out for you, I'm in Bitterne Park.
 
ah ok cool, I'm only a few miles away, might take you up on the offer. I'll get some photo's up after work to see if it can be solved. Just bought some bullet connectors/ solder wire and wire tape incase i need to do any fixing, or 'butcher wires'.

You wouldn't know of any places other than Sextons in town that can fix/repair a damaged headunit? I have a £400 (back in the day) JVC headunit spare which the internal amp seems to be blown perhaps. Not sure. - Gone way past it's warranty etc.

cheers
 
Ok here's a few more photos... see if this helps.

Mobile-Photo-22-Sep-2010-14-13-19.jpg


On this one below, I've labelled A and B, A = Memory wire B = Yellow wire from Headunit. When I plug these in, I get headunit memory and everything is all fine. But... this then effects my remote central locking. Ican lock the car using key and central locking works that way but not by remote central locking. As soon as I d/c the wire I lose memory obviously but then my remote central locking works. Weird! I almost want to post a video of it. lol

IS there something wrong im doing here. this is what I was left with when bought the car. I've wire taped any naked wires not in use incase of any touches against other wires to elimate any of these issues.



Mobile-Photo-22-Sep-2010-14-03-51.jpg
 
Well the Memory wire A has been added, so this is what is causing the problem. Which is wierd as there is no need for it as there is a perm live already on the original black power ISO. So I would trace back the new A wire and disconnect it. It is a permanent live so I wouldn't just isolate it.
Then you just relocate your B cable from the HU into the perm live slot on the original Audi power connector, the black one that is plugged in underneath the brown front speaker ISO.
The wire you need is the fat red one with white stripe which is immediately above the fat brown earth cable, top right when looking at the back of the connector (where the wires come out). You may want to check this is live and check the fuse in the fusebox if it isn't (fuse shown as Radio in the handbook) as I can't think why they would have gone to all the trouble of wiring in a second permanent live feed.
I would also investigate what they have done on the speaker front as it looks like they have rewired the rear speakers back to the HU as you have a whole bunch of additional wiring there and an additional adapter that is unnecessary. If they have rewired the rears then the RCA adapter you have wired up will only be driving the subwoofer, which will be very quiet as a result as it is only 50w and the Pionner will be kicking out more than that to the cabin speakers.
 
Right, I'm determined to get this sorted. Never had this much trouble with wiring a headunit in before. Nightmare!
Well the Memory wire A has been added, so this is what is causing the problem. Which is wierd as there is no need for it as there is a perm live already on the original black power ISO. So I would trace back the new A wire and disconnect it. It is a permanent live so I wouldn't just isolate it.
I'll have to trace this and find out where it's hsoted, I've had a new battery pu tin yesterday and so it's not manually attached to the positive so muct be attached to something else within the cockpit of the car.

Then you just relocate your B cable from the HU into the perm live slot on the original Audi power connector, the black one that is plugged in underneath the brown front speaker ISO.
The B connector is what i made up, shoddy way, but It's still connected to the black harness, all I have done was stripped back about half a cm of wire and soldered an extra wire from it so it splits basically.[/QUOTE]

The wire you need is the fat red one with white stripe which is immediately above the fat brown earth cable, top right when looking at the back of the connector (where the wires come out). You may want to check this is live and check the fuse in the fusebox if it isn't (fuse shown as Radio in the handbook) as I can't think why they would have gone to all the trouble of wiring in a second permanent live feed.
I'm not sure why they would of gone to the trouble maybe they had the same problem and didn't ask for help or research into swapping the two main wires for it to work.
This is the main thing I need to look into when i get in from work tonight, fat red wire? from the pic at the moment all I see is two red wires. no white stripe. Which connector are we talking about as there's 4/5. the main earth, power, switch, memory from the headunit? or ones closer to the audi loom?


I would also investigate what they have done on the speaker front as it looks like they have rewired the rear speakers back to the HU as you have a whole bunch of additional wiring there and an additional adapter that is unnecessary. If they have rewired the rears then the RCA adapter you have wired up will only be driving the subwoofer, which will be very quiet as a result as it is only 50w and the Pionner will be kicking out more than that to the cabin speakers.

Don't worry about this, I think there was an extra harness put in so it was effectively an extension. I have now removed this. so it should be as standard. The speakers are working fine and correctly from the rears also. I reckon they put in aftermarket speakers front and back as people say the sound system is a little naff. And the sound I'm getting at a high level is pretty good quality and the sub is handling fine. - I remember sorting a similar issue out on here before with your help.


I'll try and have another solid look for this red wire with white stripe down it. WIll take better pictures of the harnesses if need be. If not start of next month might require your helpful services. :eyebrows:

:icon_thumright: cheers for this info.
 
As suggested to you, just put a new positive feed from your battery (fuse box) to the remote. All it is is a positive connector to complete the circuit. Over the few years I have been driving I have done this several times on various audio devices for cars.
 
As suggested to you, just put a new positive feed from your battery (fuse box) to the remote. All it is is a positive connector to complete the circuit. Over the few years I have been driving I have done this several times on various audio devices for cars.
Yeah i know, but i don't exactly know how to do this. As in where to feed the wire through and how to attach it?


I have a pic of a better view of the wires. I've found the red and white wire and it is connected to the red at the headunit. So do I just swap the red and yellow over? bullet connect the red and switch over?

Photo-Sep-24-9-30-28.jpg
 
the red/white is the permanent live, so should go to the yellow on the HU. On that same connector, do you have a yellow with red stripe?
If so then that is the switched live and needs to go to the red wire on the HU.
If not then you either pair both yellow and red wires together and connect them both to the red/white on the connector and turn the HU on/off manually, or you will need to run a feed from the back of the fusebox, look for Radio S-Kont in the manual this is the correct fuse for proper switched live. You should have one as your car is a 2000 and this is when they switched from a normal switched ignition on live wire to using the CANBUS instead. But early cars still had the fuse for the old normal system.
 
Apoligies for my late reply been away. Trail a wire from fuse box to the back of your engine bay, then look for any seal/hole/ where anything trails through to inside the car. Preferably close to the back of the head unit.

Then you can be as neat as you want to get the wire to the back of the head unit.

Think this is the easiest, although not simplest route to take to solve the problem. If you could pick up on a permanent feed inside the car this will also help as this requires literally next to no ampage. Is the cigarette lighter a permanent feed? You could T off the live on that if it is.
 
Wahey, finally I have sorted it out now. Such a relief and so painful. I've got it all working thanks to you AndyMac. Found the yellow and red wire and followed it through swapped them over by the headunit harness and all is good. Remote central locking works as well as the HU memory.
I didn't find time to see where that spare yellow wire came from but have hidden it and tapped the connection off. Thanks for your patience. :)
 

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