OEM LED inner tail light wiring DIY

[DkN]

Well I dug up my old DIY over from golfmkv which is pretty dead these days, decided to put it up here.

This DIY relates to the OEM LED tail lights which come with no LEDs in the inner tails. To put LEDs in there without any hassles, PM Buckets who will do it all for you for a fee, with LEDs that perfectly match the colour of the outer tails. This DIY only explains the wiring which is a PITA since there are no pre-buried parking / brake wires for the inner tails.

AFAIK there are two ways of wiring these, one is the easier method which threads the wires through the hatch door up to where it joins to the body of the boot, and then poking it out of the rubber connector tube, into the rubber seal and into the side of the boot. This obviously has minor cosmetic issues and at one point you'll see the wire sticking out a bit, but it's not too obvious. This is the option that TDI_DSG took and it was the method he suggested to me when I asked for help.

The other option is to thread it all the way through the rubber connector tube and into the narrow passage that's built into the boot body for existing wires. This is a lot more difficult to achieve but will look perfect as you cannot see the wires at all. I opted for this method, and this is what I will be providing a DIY on.

What you will need:

10mm hex ratchet
screwdrivers (flathead and philips)
pliers
a small knife (maybe)
3m of electrical wire, positive and negative
2x crimp-on connectors and 4x terminals (I used the bullet type)
a rigid metal wire of more than 50cm in length
a helping hand (may not be absolutely necessary but will make things MUCH easier)
a lot of patience

Note: all directions i.e. up, down, left, right, top, bottom, are relative to the position where the boot is fully open. All pictures are shown with the right way up i.e. no tilted photos.

Begin with taking the LEFT outer tail lights off the car. This will give you more room to manoeuvre, plus you'll have to wire the inner LEDs to the plug in any case. This is a simple matter of peeling back the trim in the boot at the sides and undoing two bolts and unplugging the lights, if you don't know how to do that there’s plenty of guidance on this topic, do a quick forum or google search. You may leave your right outer tail lights intact.

After that you'll have to take off the inners. Now since the bolts for the inners are rather hard to reach if you just peel off the cover on the inside of the hatch door, and since you have to take the entire inside cover of the hatch door off anyway, pull off the whole plastic cover first. There's a good DIY here. The 4th, 5th and 6th pictures are the ones you'll need.

When that is done, note the rubber hose-like connectors between the hatch door and the boot body, on either side. Go to the left one, pull either ends of it out of the metal. The top end (connected to the hatch door) is just a grommet, and the bottom end (connected to the boot body) is a clip, just peel the left side of it and it will pop out. Picture of the removed connector as below. Note I took these photos halfway through so the wiring is already in place.



Take your wire (positive and negative). Get a flathead screw driver and pry open the bottom corner of the white plastic cover (you can see the pry marks from where I did it in the picture above - you should probably be more careful ) enough so that your wire can squeeze through. You may find that you need to pry it until a clip pops loose, depending on how thick your wire is. Alternatively you could remove the whole trim, but I couldn't be bothered to. Then you need to thread the wire through downwards, enough so that when you put your finger through the hole where the rubber grommet for the connecting tube was, you can feel the wire. Once you can hook your finger on the wire, thread it through the hole and yank it down until there’s enough length to reach down to where your outer tail lights are.

Next you have to thread the wire through the rubber connector (as picture above). The black wire you see in the middle of the picture is the one that I used, and you can see it coming out of the bottom of the tube.

With that done, now we move on to the most difficult part of the wiring. You have to thread the wire through the bottom hole where the rubber tube will sit over, into the side of the boot.

Here's where it has to go through:



And here's where it has to come out:



There are several dead ends through that path that you might hit so this will take up the bulk of your time. A rigid metal wire here is really essential for this to work. The wire needs to be rigid enough that it is difficult to bend out of shape by hand and use of pliers may be required. It helps if when you're poking the wire through, it is bent at the tip slightly towards you, like so:



Poke that wire through the hole at the top of the boot body. When you get stuck, move it back and forth while wiggling it a little until you feel it sink deeper (I know what you're thinking you dirty bastard). Mine got stuck at about 3 or 4 different "levels" before it successfully broke through. You'll be able to see it clearly in the space where you peeled the boot trim back - if you can't, don't go groping for it in hopes of finding it - you most likely poked it through the wrong path and you'll just reward yourself with cuts on your hand.

At this stage if you decided to give up on this method you can still carry on with TDI_DSG's method of poking a hole in the rubber connector tube and the rubber seal around the boot body, threading it through to the space where it needs to be. You'll need to seal the places where you poke the hole. Pictures of this are in the next post.

If you succeed, once you're through with your metal wire, tape the end of your electrical wire to the end of your metal wire and pull the whole thing through. Make sure you have enough overlap i.e. at least 10cm of of the end of your metal wire should overlap with the end of your electrical wire, where it's taped - if your electrical wire comes loose from the tape when you're pulling it through then it's back to the beginning, to thread your guiding metal wire all over again.

Once your electrical wire is through, cut the tape and ditch the guiding metal wire, and you can get to the wiring. I didn't take pictures of the process, but the plug that plugs into your outer taillight has numbers 1-4 written on each pin. This thread will give you a description of what each one does (for Australia, we have the 4-pin connector just like the Euro version, so disregard the 3-pin comments). What you need to connect to your positive is the wire in position 3 if you'd like your inners to have parker function only, or position 2 if you'd like your inners to also have brake function. The last wire in position 4 is the common ground that you will wire your negative to. Use the crimps of your choice to hook your wires up. NOTE: if you want the quad ring effect through VCDS, you MUST wire the inners as parkers only in position 3.

Once that is done, it would be a good time to test your wiring. Come back to the other end of your wire that is yet to be connected. Now look and find the approximate section in the middle where it will connect to the wires for your LEFT inner tail when they are in position. Cut open the rubber at that point and expose approximate 15mm of wire. Bend that section up in a “V” shape, twist it together, and crimp on terminals (or you can solder but who does that ). Crimp on the connecting terminals on your LED wires. Plug them in, turn on your lights and check if they work as expected. Also check that your terminals are crimped on properly and are making proper connection with the wires. terminals are preferred as the lights will still be removable later.

Once you're sure the lights are working, you can unplug them and finish off hiding your wires. Starting from the bottom corner of the white plastic cover inside your hatch door, pry it open (if you didn't remove the whole cover before) and stuff that part of your wire inside, and work your way up slowly along the side of the cover. Once you’re finished your wire should be fully inside the cover, like so:



And there you have it! One side is completely done. The good news is that you don’t have to repeat the painful process for the other side. This is the reason why you got 3m long wires – it simply runs through to the other side :happyanim: Crimp on your terminals at the remaining end of the wires, and crimp on the connecting terminals to your other LED inner’s wires. Now just plug them in, and run a final test. If all is well, just proceed to put everything back and you’re done. With reinstalling the black plastic cover, it helps to clip in the top half first.

End result (crappy pic as it’s dark and I have my back pressed up against my garage wall, but you get the idea):



Next step is to do the quad ring VCDS mod.

[DkN]

Ran out of characters in the first post - here's a pic of the whole shibang in the hatch door to show the wire running straight to the other side. I've threaded the wire through the little gap across the middle so it doesn't dangle down. Zip ties would also help with the excess length to the right.

[DkN]

Here are the pictures of TDI_DSG aka Jason's method. Note photos are of the right side.





So you'll need to poke two holes, one in the rubber tube and another in the side of the boot, under the seal around it. After that just seal whatever gaps created with your choice of sealant.

[veedubin77]

Well I dug up my old DIY over from golfmkv which is pretty dead these days, decided to put it up here.

This DIY relates to the OEM LED tail lights which come with no LEDs in the inner tails. To put LEDs in there without any hassles, PM Buckets who will do it all for you for a fee, with LEDs that perfectly match the colour of the outer tails. This DIY only explains the wiring which is a PITA since there are no pre-buried parking / brake wires for the inner tails.

AFAIK there are two ways of wiring these, one is the easier method which threads the wires through the hatch door up to where it joins to the body of the boot, and then poking it out of the rubber connector tube, into the rubber seal and into the side of the boot. This obviously has minor cosmetic issues and at one point you'll see the wire sticking out a bit, but it's not too obvious. This is the option that TDI_DSG took and it was the method he suggested to me when I asked for help.

The other option is to thread it all the way through the rubber connector tube and into the narrow passage that's built into the boot body for existing wires. This is a lot more difficult to achieve but will look perfect as you cannot see the wires at all. I opted for this method, and this is what I will be providing a DIY on.

What you will need:

10mm hex ratchet
screwdrivers (flathead and philips)
pliers
a small knife (maybe)
3m of electrical wire, positive and negative
2x crimp-on connectors and 4x terminals (I used the bullet type)
a rigid metal wire of more than 50cm in length
a helping hand (may not be absolutely necessary but will make things MUCH easier)
a lot of patience

Note: all directions i.e. up, down, left, right, top, bottom, are relative to the position where the boot is fully open. All pictures are shown with the right way up i.e. no tilted photos.

Begin with taking the LEFT outer tail lights off the car. This will give you more room to manoeuvre, plus you'll have to wire the inner LEDs to the plug in any case. This is a simple matter of peeling back the trim in the boot at the sides and undoing two bolts and unplugging the lights, if you don't know how to do that there’s plenty of guidance on this topic, do a quick forum or google search. You may leave your right outer tail lights intact.

After that you'll have to take off the inners. Now since the bolts for the inners are rather hard to reach if you just peel off the cover on the inside of the hatch door, and since you have to take the entire inside cover of the hatch door off anyway, pull off the whole plastic cover first. There's a good DIY here. The 4th, 5th and 6th pictures are the ones you'll need.

When that is done, note the rubber hose-like connectors between the hatch door and the boot body, on either side. Go to the left one, pull either ends of it out of the metal. The top end (connected to the hatch door) is just a grommet, and the bottom end (connected to the boot body) is a clip, just peel the left side of it and it will pop out. Picture of the removed connector as below. Note I took these photos halfway through so the wiring is already in place.



Take your wire (positive and negative). Get a flathead screw driver and pry open the bottom corner of the white plastic cover (you can see the pry marks from where I did it in the picture above - you should probably be more careful ) enough so that your wire can squeeze through. You may find that you need to pry it until a clip pops loose, depending on how thick your wire is. Alternatively you could remove the whole trim, but I couldn't be bothered to. Then you need to thread the wire through downwards, enough so that when you put your finger through the hole where the rubber grommet for the connecting tube was, you can feel the wire. Once you can hook your finger on the wire, thread it through the hole and yank it down until there’s enough length to reach down to where your outer tail lights are.

Next you have to thread the wire through the rubber connector (as picture above). The black wire you see in the middle of the picture is the one that I used, and you can see it coming out of the bottom of the tube.

With that done, now we move on to the most difficult part of the wiring. You have to thread the wire through the bottom hole where the rubber tube will sit over, into the side of the boot.

Here's where it has to go through:



And here's where it has to come out:



There are several dead ends through that path that you might hit so this will take up the bulk of your time. A rigid metal wire here is really essential for this to work. The wire needs to be rigid enough that it is difficult to bend out of shape by hand and use of pliers may be required. It helps if when you're poking the wire through, it is bent at the tip slightly towards you, like so:



Poke that wire through the hole at the top of the boot body. When you get stuck, move it back and forth while wiggling it a little until you feel it sink deeper (I know what you're thinking you dirty bastard). Mine got stuck at about 3 or 4 different "levels" before it successfully broke through. You'll be able to see it clearly in the space where you peeled the boot trim back - if you can't, don't go groping for it in hopes of finding it - you most likely poked it through the wrong path and you'll just reward yourself with cuts on your hand.

At this stage if you decided to give up on this method you can still carry on with TDI_DSG's method of poking a hole in the rubber connector tube and the rubber seal around the boot body, threading it through to the space where it needs to be. You'll need to seal the places where you poke the hole. Pictures of this are in the next post.

If you succeed, once you're through with your metal wire, tape the end of your electrical wire to the end of your metal wire and pull the whole thing through. Make sure you have enough overlap i.e. at least 10cm of of the end of your metal wire should overlap with the end of your electrical wire, where it's taped - if your electrical wire comes loose from the tape when you're pulling it through then it's back to the beginning, to thread your guiding metal wire all over again.

Once your electrical wire is through, cut the tape and ditch the guiding metal wire, and you can get to the wiring. I didn't take pictures of the process, but the plug that plugs into your outer taillight has numbers 1-4 written on each pin. This thread will give you a description of what each one does (for Australia, we have the 4-pin connector just like the Euro version, so disregard the 3-pin comments). What you need to connect to your positive is the wire in position 3 if you'd like your inners to have parker function only, or position 2 if you'd like your inners to also have brake function. The last wire in position 4 is the common ground that you will wire your negative to. Use the crimps of your choice to hook your wires up. NOTE: if you want the quad ring effect through VCDS, you MUST wire the inners as parkers only in position 3.

Once that is done, it would be a good time to test your wiring. Come back to the other end of your wire that is yet to be connected. Now look and find the approximate section in the middle where it will connect to the wires for your LEFT inner tail when they are in position. Cut open the rubber at that point and expose approximate 15mm of wire. Bend that section up in a “V” shape, twist it together, and crimp on terminals (or you can solder but who does that ). Crimp on the connecting terminals on your LED wires. Plug them in, turn on your lights and check if they work as expected. Also check that your terminals are crimped on properly and are making proper connection with the wires. terminals are preferred as the lights will still be removable later.

Once you're sure the lights are working, you can unplug them and finish off hiding your wires. Starting from the bottom corner of the white plastic cover inside your hatch door, pry it open (if you didn't remove the whole cover before) and stuff that part of your wire inside, and work your way up slowly along the side of the cover. Once you’re finished your wire should be fully inside the cover, like so:



And there you have it! One side is completely done. The good news is that you don’t have to repeat the painful process for the other side. This is the reason why you got 3m long wires – it simply runs through to the other side :happyanim: Crimp on your terminals at the remaining end of the wires, and crimp on the connecting terminals to your other LED inner’s wires. Now just plug them in, and run a final test. If all is well, just proceed to put everything back and you’re done. With reinstalling the black plastic cover, it helps to clip in the top half first.

End result (crappy pic as it’s dark and I have my back pressed up against my garage wall, but you get the idea):



Next step is to do the quad ring VCDS mod.

Help, im from the states. where do i order those lights already moddded?