DIY - Tail Light Connector Replacement

[TheWulf]

Disclaimer: I assume no responsibility whatsoever for damages that an end user may inflict upon their vehicles or themselves using information contained herein. Proceed with caution and care when performing modifications to your vehicle. Be advised
that making modifications to your vehicle may void your manufacturer's warranty and may not be legal for road use depending on your location.

Background: So I have been dealing with alerts on my dashboard stating that my rear left reverse light, rear left brake light, and rear left light all have been out. Didn't take long to diagnose issue. I pulled out the light assembly and BOOM, had a short. As you will see my short was bad so the outer bulb carrier had to be replaced as well as the connector. In your case hopefully you will not have to replace the whole outer bulb carrier and the connector.

Tools required:
-Small Flat Head Screwdriver
-Wire Cutters
-22-18 wire gauge butt connector (https://www.harborfreight.com/10-pac...ors-66595.html) (if you are able to secure a connector with pigtails)
-Small Terminals (https://www.ecstuning.com/b-genuine-...ach/n10335807/) (Use only if you don't have to purchase a new connector)
-Terminal crimpers (https://www.amazon.com/Tool-Aid-1890.../dp/B0002STTSY) (these can be used on the "Small Terminals")
-Wire Stripper (can use a stripper/crimper combo, that's what I used)
-Multimeter
-Outer Bulb Carrier (https://www.ecstuning.com/b-genuine-...ft/8e5945257c/) (Link is to the sedan left, they have others available)
-Terminal Removal Tool (https://www.ecstuning.com/b-schwaben...ieces/ce-70-2/) or (https://www.idparts.com/vw-pin-remov...2da1c03a73f174)
-Connector (https://www.ecstuning.com/b-genuine-...ng/3d0973733g/) (Please verify this is the correct part number on your car, the OEM part number should be molded into the plastic connector on the outside face)
-Fresh bulbs (might as well have them on hand since you're already here)
-VAG Connector Removal Tool (not needed but very usually especially for other parts of the car) (https://www.ecstuning.com/b-schwaben.../002916sch01a/)

Step 1
Remove the Tail Light assembly from the body (I'm not going to list a step by step but you can follow the steps in the video below)
https://www.youtube.com/watch?v=I-H9WjqtjEQ
You don't have to use the tape if you don't want to.

Step 2
Verify the short and determine if you need to simply push the terminals out of the connector and replace with new terminals or in my case I was able to secure a pigtail connector assembly off a car in my local pick and pull



The ground pin on my outer bulb carrier was brittle, so I had no choice but to buy a new carrier, luckily I also got one of those from the local pick and pull. Otherwise ECS carries them for a good price.

Step 3
Use a multimeter to ensure the lines are not live. On my car I had 4 live wires and 1 ground (brown). I tested the voltage between the ground and all four wires individually to ensure none were live prior to cutting the wires. You can disconnect the negative on the battery as well but I would still double check to be on the safe side.

Step 4
If all you have to do is replace a couple of terminals in the connector you can follow the instructions in the following video using a couple of tools listed above. If you have to replace the whole connector skip to step 5.

https://www.youtube.com/watch?v=kUtE...ature=youtu.be

or

https://www.youtube.com/watch?v=5rlXZUvhEsQ

Be careful removing the terminals because they small and can bend easily. After crimping on the new terminals and installing them into the new or existing connector I would use the multimeter to test the resistance between each pin to ensure that the insulation in the connector is adequate. Only after checking the resistance would I check for power to the pins. Better to check first rather having to do double the work or even having to replace parts due to negligence.

Step 5
If you have a pigtail assembly cut the wires to the same length before the grommet, or after the grommet if you have access to the internal compartment.

Cut the wires on the connector on the car at the same length as the new or replacement pigtail assembly.


Step 6
Strip the wires on the car and the wires on the new or replacement pigtail assembly at the same length and insert into the butt connector. You can solder them together if that's your forte, but ensure that you have enough heat shrink to provide insulation between the wire bundle. Make sure you match the wire colors of the flying leads from the car to the pigtails on the new or replacement connector assembly.


Step 7
If needed, connect the new or replacement outer bulb carrier to the tail light housing. Otherwise skip to Step 8.

Step 8
Reconnect your battery and perform the ECU reset per the factory manual. Then repeat Step 3.

Step 9
Check the function of the new assembly by turning on your tail light and using a multimeter to check the voltage supply per each function of the tail light (i.e. braking, turn signal, running rear tail light, reverse light)
Or you can simply plug your new connector assembly into the outer bulb carrier and perform the same functional testing.


Step 10
If all is well reinstall your tail light assembly and make sure that the alarms on the dashboard have gone away.


Step 11
Go wash your dirty a$$ car, or at least that's what I did

If I'm missing something let me know.

[sastanley]

I know this is an old thread, but this is the same problem I am trying to solve. I even called sales at ECS Tuning, and they said "all the parts are on our sight but we can't tell you which ones to get, or cut a pig tail at a junk yard, good luck."
Can anyone verify the small terminals from ECS (ES#467999, VW#N 103 358 07) that Wulf linked to are in fact the correct ones for that connector? I found the empty connector at ECS (ES#351195) (VW#3D0973733G) and want to use those terminals if they fit in the connector...essentially assembling my own pigtail. My assembly still works if I take it apart and clean it and re-assemble, but I am getting warnings for both sides every week or so, and the condition of my connector is not too far behind the OP's.
I think the cause of this issue is that the ground wire is too small and gets overloaded/hot/burnt with extended high demand & usage over time (i.e., lots of long brake light)...that is my theory anyway.

[PNW Avant]

I would recommend ordering/emailing from audiusaparts.com. Not only will it be cheaper than ECS but if you give them your VIN they will help you with what you are trying to order. If you have confirmed the plug part number, they will be able to tell you (and sell you) the appropriate repair wire for the plug. They helped when i was trying to find a repair wire for my SQ5 exhaust valve harness. Also, i'd recommend getting the repair wire (rather than the terminal) unless you have the proper crimping tool for these VAG pins.

I am having the same issue right now - both sides! Waiting for another new tail light and parts to fix both connectors.

[Scourge]

Thank you Mr. Wulf: Just finished same issue on 2012 A3 S-line. Pigtail $80 Outer bulb holder $80 Misc. $10 Biggest problem was finding correct pigtail at findpigtails.com sent pics/done.