Problems with new Headunit installation!!

M

Mark Morb

Member
Hi,

I have just tried to change the HU in my Audi A2 but have hit a problem.
I am trying to replace the Standard unit with a Pioneer 5100UB.
There does not appear to be any power reaching the HU, when I turn the ignition on the unit is dead...when I unplug the ISO connector and plug it back into the factory HU then that works fine!!
I have tried the 5100UB in my partners car and as soon as I connected it to the ISO and switched the ignition on it burst into life.
I am very confused as the HU is obviously ok and the ISO connectors will power the factory HU just fine...
Any ideas? I'm stumped...

Thanks,
Mark
 
This is because the standard Audi implementation of the ISO connector isn't the same as the standard version. You'll have to move or double up on the power feed and note that there's no post ignition feed to the connector - Audi headunits get this ifo from something called CAN bus, which tells the radio when the ignition is on, and the headunit then sources a 12V feed from the permanent feed internally.

Cheers,

Mike
 
Could I get round this by joining the ignition and permanent live connections on the HU side of the ISO connector?
 
Not without voiding your warranty. Why not see if someone like Autoleads does a specific adapter for your headunit?

Cheers,

Mike
 
Right then, what you'll need to do is to alter the loom adapter to give the correct feeds to the Pioneer - use the install book from the Pio h/u and then splice the adapter to give the needed feeds.

The large brown wire on the Audi side is the main earth and the red/white wire is the 12V permanent feed, so take it from there.

BTW, what year is the A2 that you're fitting the Pio to and what wiring is at the Audi connector?

Cheers,

Mike
 
Thanks for your help with this Mike, I haven't had the chance to try yet but intend to over the weekend.

It's an '04 1.4SE

Audi side connections are two ISO blocks and a third block for the rear speakers.....Autoleads adapter accepts both ISO block and has a block to RCA lead for the rears (the RCA's can go into the Pioneer HU)

Something else I've also noticed is that everytime I start the car after a few seconds I get a "beep" and the sound from the factory HU fades and then comes back after a few seconds!!

Mark,
 
If you can post details or a photo of what is needed at the Pioneer end, I can let you know how to mod the harness adapter.

Cheers

Mike
 
Skipton01 said:
If you can post details or a photo of what is needed at the Pioneer end, I can let you know how to mod the harness adapter.

Cheers

Mike
Click to expand...

That would be incredibly useful and very generous of you...

Here's a link to the wiring diagram:

3992637924_8092382d14_o.jpg


Thanks,
Mark
 
Hmmm, just downloaded the full manual from PioneerUK and it looks like you're going to have to go fishing for a feed or 2, as it specifically says that you may suffer from a flat battery unless the ignition wire is correctly installed.

So, let me look into it and get back to you later.

Cheers

Mike
 
Skipton01 said:
Hmmm, just downloaded the full manual from PioneerUK and it looks like you're going to have to go fishing for a feed or 2, as it specifically says that you may suffer from a flat battery unless the ignition wire is correctly installed.
So, let me look into it and get back to you later.
Cheers
Mike
Click to expand...

Things are never easy are they :rolleyes:

Thank you very much with your help on this though....it's very much appreciated.

Thanks,
Mark
 
OK, what you need to do to get the correct feeds is the following:

You have a thick red/white cable going to the black 8 pin Audi connector - this is a permanent 12 volt feed and there is also a similar thickness brown cable below it - this is the earth.

You now need to remove the climate panel (push from the back) and take a couple of feeds off the wiring at the back of it.

There is a very thick white wire going to a 2 pin connector - this is switched positive. You can also take a feed from the thick black/blue wire going to pin 3 of connector D - this will suffice for an illumination feed (it isn't one, but if you want a proper illumination feed, you'll have to tap a wire from pin 17 at the light switch, which is grey/blue).

Feed these into the correct places on the wiring loom adapter and bobs your uncle

Cheers,

Mike
 
Thanks so much for that Mike...
I will not get the chance to try it out until Saturday but feel a lot more confident now.
Much appreciated, I'll let you know how I get on..

Thanks again :)
Mark
 
No worries - any problems, give me a shout.

Also, please try to tap the wiring by soldering, not using those awful snap lock connectors - they can cause fires in extreme circumstances and are to be avoided at all costs.

Cheers,

Mike
 
Hi Mike,

Well I'm in the middle of doing it...couple of things. I cannot seem to get the Climate panel out...and I cannot get the rear speakers to work.
Does the red rear socket need power?
The adapter I have only seems to have 4 wires coming from the socket going to the RCA plugs, there are a couple of wires in the Red Audi side that have nothing going in to them?

Thanks,
Mark
 
bretti_kivi said:
the climate panel is clipped into place. The rear speakers run off an active amp and need power / output.

Bret
Click to expand...

Thanks...I've been searching for a wiring diagram but to no avail.
Does anyone know the wiring layout for the rear speaker/amp plug...

Thanks,
Mark
 
OK, Sussed it....I needed to connect a switch feed to the rear amp...all works great now.
Except...I still have that really annoying beep after a few seconds!!! The factory HU did that as well...
 
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