Headunit Install

[stephen8512]

Hey guys

Looking to install a HU into the MK3. Found this wiring diagram by doing some searching :

http://faculty.ccp.edu/faculty/dreed.../VW-Wiring.pdf

and also found this :

Wiring Adaptor for Mk3 Golf OEM Radio to suit Aftermarket

The wiring diagram would have helped if I was to try and solder the new HU connector wires into it but I just decided to grab the Aerpro APP7201 male ISO connectors to save time. Only cost 15 bucks from supercheap.

APP7201 harness on the right, the Pioneer HU harness on the left.


My question is, I was looking at the harness inside the dash and I noticed one of the wires was cut.



It looks like a black wire from the black connector, and looking at the wiring diagram, couldnt seem to find any black wires coming from that connector.

Bit of a longshot but any idea what this wire is/does and whether I can hook up the new unit without this wire?

Also, I noticed that the plug where the radio connector hooks up to the HU is different on the OEM unit compared to my Pioneer HU. (bottom left of the headunit in the photo below)



The radio cable inside the dash is a female connector, hooking up to the male end of the OEM headunit, whereas it seems like I need a male connector to hook up to the female end of the aftermarket one?

Any help would be appreciated

Cheers

[dylan8]

Normally require an adapter for the aerial on vws

[cliftronix]

The adapter can be found at any Jaycar store for about 3 bucks, Its called a Motorola to euro aerial adapter if i remember correctly.

[BurgundyMk3]

I had a fair bit of trouble getting the right adaptor for my pioneer unit. Ended up cutting up the factory wiring and soldering (twist and tape)
I do remember having to switch a few wires around in the factory plugs to actually get mine to work

Sent from my GT-I9305 using Tapatalk

[Mk3 AAA]

You'll find the car also has two aerial plugs which may be a little confusing at first, but that's because the loom is a Frankensteinian webbed entanglement of the VR's and Vento's.

[stefcio007]

I ended up having one cable from the original unit loose. Not too sure what it does but never caused problems. I actually think it's to turn on and off the lighting on the OEM unit. New units have the lights always on so it's not needed. Can't remember what colour it was.
I did the same as burgundy and cut the original connector off and wired the new connector in.
Looks like Sony and Pioneer use the same connectors, wonder if the pin out is the same.

[stephen8512]

Normally require an adapter for the aerial on vws

The adapter can be found at any Jaycar store for about 3 bucks, Its called a Motorola to euro aerial adapter if i remember correctly.

Thanks guys I'll check Jaycar

You'll find the car also has two aerial plugs which may be a little confusing at first, but that's because the loom is a Frankensteinian webbed entanglement of the VR's and Vento's.

This is what I found. It wasn't hooked up to the OEM deck though. Is there another cable similar to this? I couldnt seem to find it. I was just feeling through the loom to see if i could feel something that felt similar but no dice?

I ended up having one cable from the original unit loose. Not too sure what it does but never caused problems. I actually think it's to turn on and off the lighting on the OEM unit. New units have the lights always on so it's not needed. Can't remember what colour it was.
I did the same as burgundy and cut the original connector off and wired the new connector in.
Looks like Sony and Pioneer use the same connectors, wonder if the pin out is the same.

So you just soldered the new headunit wires into the factory harness? Did it take long?

[stefcio007]

So you just soldered the new headunit wires into the factory harness? Did it take long?

I used a connector block and soldered a few.
I basically had the old unit connected and connected a speaker at a time to figure out which one it was, then wired it into the correct cables on the new stereo connector.
I don't think it should take too long, the power cables are pretty obvious and use a multimeter if you aren't sure. The great thing is when I wanted to upgrade my sony unit, just unplugged the old one and plugged in the new one (also Sony). Easy.

Mine was OEM wiring, but the rear speaker wiring felt aftermarket, the speakers were very old though and definitely OEM. For some reason I have 5.5" speakers in the rear...did anyone else have this?

[stephen8512]

I used a connector block and soldered a few.
I basically had the old unit connected and connected a speaker at a time to figure out which one it was, then wired it into the correct cables on the new stereo connector.
I don't think it should take too long, the power cables are pretty obvious and use a multimeter if you aren't sure. The great thing is when I wanted to upgrade my sony unit, just unplugged the old one and plugged in the new one (also Sony). Easy.

Mine was OEM wiring, but the rear speaker wiring felt aftermarket, the speakers were very old though and definitely OEM. For some reason I have 5.5" speakers in the rear...did anyone else have this?

Im pretty crap when it comes to electricals and I dont have a multimeter myself so it'll be a lot of trial an error if I were to go down your route. May need to invest in one when I get the heatshrink and antenna adaptor thingo from Jaycar...

The Aerpro APP7201 universal harness I got seems to just clip in to the factory harness (black to black, brown to brown) and then it has the different coloured exposed wires for me to solder into. I was going to just solder the wires from the Pioneer HU wires and match the colours to the harness and hope it works.

I had 6.5" speakers in all 4 door cards and 6" for the rear parcelshelf. I plan to just get 6.5" component speakers for the front and rear, and some 6x9's for the rear parcels. The two speakers on top of the dash I'm just going to disconnect as I think they're the splits?

[browntown42]

That is the aerial as far as I'm concerned, you need to buy another extension piece like the others have said to be able to plug it into the back of the headunit

As for the black wire, When installing my subs and amp, the black wire I spotted was the remote wire which is used to connect your headunit to the amp. It isn't used if your just connecting the speakers to the headunit.
But whoever did install my previous headunit didn't use any adapters and splice and soldered each connection so it was hard trying to find which cord did what.