UK-POLOS.NET - THE VW Polo Forum

Hi everyone,

I've just got a new Joying headunit https://www.carjoying.co.uk/best-joying ... ntrol.html for my 03 Polo 9n.

Once I've installed the headunit there seems to be power still going to the unit even once key is out also the central locking from the key fob stopped working. Picked up two adapters for the wiring from Halfords (please no hate) with no luck with the guys there not having much of a clue to whats happening with it. After some research seems to be an issue with VW's when upgrading the stereo etc. Couldn't make much sense on other forums as most of them broke out in to arguments but if someone could point me in the right direction that would be great.

Cheers,
Jack

A few things to bare in mind about VAG ICE wiring, there will be a switchable main power in lead and a memory support permanent power feed, also a lead to feed the powered aerial and lastly, some wiring to support on board diagnostics.

So, mess any of these up and you will probably have problems, now if you have taken a VW radio out, you should be able to work out which wire does what, and take it from there.

If you don't know anything about car electrics, I'd get professional help.

Assuming the adaptor leads are correct - you sometimes have to transpose the yellow and red power leads when fitting new units - one lead will be for memory (permenant live) and one will be for unit power (from ign and switchable),I usually try the new unit out a few times before finally locking in place (ie switching off - removing key etc and seeing if it retains memory for presets).

I had the permanent live problem just recently when fitting my new headunit which funnily enough has no power button sohad to sort it, I used a multimeter to find which wire was the ignition on the car's wiring which wasn't the standard yellow or red!

The OP had bought a wiring adaptor though - which may have a yellow/red wire on the head unit side of the adaptor.