Help with wiring

[Slo_Ride 5,000+ posts]

I'm not a VW expert but here goes...

Yellow wire is your constant 12v power wire. Red is you Ignition or switched 12v wire. If the red wire is hook to a constant 12v source then there is your problem. You say you switched the red and yellow wire? You may have to find you own 12v switched (ignition) source.

 

[Hopeless]

Thanks Slo_Ride,

is there any way of switching the red wire to another source?

 

[Slo_Ride 5,000+ posts]

From what I've read the last couple of minutes the stock VW radio did not use a switched power source so you will have to cut the red wire and connect it to a switched power source.

 

[CrossoverOre 10+ year member]

stop doing what you are doing. Those vw's use can bus to turn the radio on and off. the red and the yellow wire coming from the aftermarket harness are both constant. Fix: rewire red wire from the deck to a acc source in the fuse panel or buy the radio interface module. this particular module will maintain the factory steering wheel controls. BestKits

 

[Hopeless]

Thanks CrossoverOre,

Thank you for that clarification.

This evening I have been looking at running a wire from the fuse box to the stereo, so it is reassuring you suggest the same thing.

My plan was to acquire a add-a-circuit fuse holder, stick a fuse in it, buy a wire and a connector for either end, connect them all up, get a volt meter, find an empty fuse hole that switches on when the ignition does, feed the wire through the dash somehow, hook up the fuse hole thing to the back of the stereo and say a quick prayer.

Does that sound sensible, and could anybody offer me advice on what fuse to use and where to stick the wire please?

 

[CrossoverOre 10+ year member]

Chances are you will not find an empty spot in the panel for the new line. vw is too **** for stuff like that. there will be empties but no pins to connect. So you could get something like 10 ATM Mini ATC Car Automotive Fuse Taps Add on Wire Adapters Auto Boat New | eBay. And the reason for this and not the add a fuse is the space, cover wont go back on if you use the add a fuse. Or drop the under knee bolster trim panel and look up. All main power lines run the a main junction right there. I think there is a acc junction there too, but might just be ign. as for which fuse just break out the meter and find a fuse that works how you want it to and then check the legend to see what it functions. I personally dont like to use any fuse thats for a majorly imperative part of the car, ie sas bcu...

 

[Hopeless]

Solved.

Using a volt meter, I found an empty fuse slot that was off when the ignition was off, and came on when the key was inserted and turned. In there I put an add-a-circuit fuse adapter with a fuse in it. Then I ran a wire from there to the back of the radio, and connected them all up, making sure constant and ignition power were connected to the right wire coming out of the radio.

Now the radio comes on and goes off with the key, and the stations and settings are still remembered. The steering wheel controls do not work, but I accepted that was the case anyway, as it was the same on all my previous cars.

Thanks very much for your help, guys.

 

[Hopeless]

So, in case there are others out there who are as hopeless as I am and would like some help, this was the solution:

The 2009 Passat radio is connected to two permanently live wires coming from the battery.

My older radio requires one permanently live wire (to remember the settings and stations), and one wire that comes on with the ignition (to switch on and off when the car is). In the past I have learned that sometimes these wires need to be swapped around, but one needs to be always live and one switched with the ignition. In the case case of the 2009 Passat, this is not the case.

So, to swap your old radio for a new one, you need to remove the old one. There are plenty of videos on the internet that show you how to do this, so I will skip that step. You will then need to put in a fascia and some kind of double DIN adapter. I bought mine at a regular car place. Again, there is plenty of help on the internet about this, so I will assume this has been done.

Once the radio is out, you will have a connector sticking out of your dashboard that looks like this:

Meanwhile, your other car stereo will have a connector that looks like this:

These need an adapter to fit together. I bought mine from a regular car place off the shelf:

Note that several of the wires, including the red one, come with bullet connectors for easy disconnection and reconnection.

Next we have to locate the fuse box (I realise there are better tools than a screwdriver to open this, but it was what I had to hand):

Get out a volt meter, as we need to find an empty fuse slot that is not live when the key is not in the ignition, but becomes live when you insert the key.

In my case, the top left fuse slot fit the bill. It is a mini-fuse.

Next, we need to run a wire from the fuse box to the stereo. I bought the wire from a regular car place again:

 

[Hopeless]

To get the wire across to the radio, I looped it through a pole from my venetian blinds, and gently pushed it through behind the steering wheel, until I could reach it through the radio slot, and pulled through the wire:

At the radio end, connect a bullet connector to the wire.

You will remember that the red wire on the adapter has a bullet connector in the middle. Just pull that apart.

Now connect your wire from the fuse box to the stereo end of the red wire on the adapter:

Though that is the radio end done now, I would keep it sitting outside of the dashboard until you are sure that the live and switched wires are the right way round. You will know this once everything is connected.

Back to the fuse box. You will need an add-a-circuit fuse holder, also known as a piggyback fuse holder. This was the only part I could not purchase on the high street, and had to order it online. You need to make sure the size you order is the same size as the fuse you picked (in my case, mini). The fuse holder looks like this:

This comes with a connector (the blue bit), so you just put the other end of the red wire into it, and squeeze it.

Finally, put the fuse holder into the fuse slot you identified, stick a fuse in the top, and voila.

Now just check that the permanent and switched power are the right way round, and you should have a stereo that remembers settings and switches off when the car does.

 

[Catbug]

Just to let you know if you were able to do this by your self do not sell your self short on being able to hook up a radio without adapters. It's nice to have them and they work perfect but you could totally wire up your own radio if you needed to. Nice job with the fix.