I had some serious front end damage a few years ago and the harness connecting to the driver's side headlight assembly got a little munched. The munching was very close to the connector so it would have been hard to cut and resplice at the damage point, especially with the wires still in the connector. So, I decided to pull the old wires with thier terminals out of the connector, and splice in new wire ends with new terminals -- soldering the connections.
Good reading before you begin:
Great page on soldering and the "telco" style solder connection:
To this I would add the following:
When twisting the wires together, twist them really carefully so there is no barb that will end up poking through your heat shrink tubing.
Use a clean pencil soldering iron. Before you solder a connection, drag the tip of your iron over a damp (not wet) sponge and silver the tip by applying some fresh solder.
Then, when soldering the connection, take a minute to heat the wires and push the solder on the wires -- not the iron -- and let the joint draw the solder in.
Then, let it cool slowly -- don't blow on it (that's just an expression .
All you ever needed to know about VW connectors and terminals:
Very nice terminal extraction tool designed for VW/Audi connectors by sold by author of awesome article above:
What you'll need before you begin:
* Pencil soldering iron and solder.
* 3/16 shrink tubing.
* New connector if you plan to replace yours.
* Repair "wire sets" available at the dealer specific to your connector. The coolest thing about these is that each one has two terminals. This lightens the bite of $3-$5 for a piece of wire with a crimped connector
* Terminal removal tool. Make your own or buy from any number of sources -- google for "lisle terminal tool" or buy the fancy set from ECS.
* Heat gun (the Milwaukee 1220 for 20.00 at Home D worked great).
We need a tool to extract the pins. Here's a pic from TDIClub of the old VW tool that I annotated with some _approximate_ measurements:
Here's a pic of the old VW tool:
These are the extractor tools I made to see which one worked best:
* By far, the one with the little wooden handle worked best for me.
The metal pieces are Bosch wiper blade supports ground down in width to about 1.5mm.
* The ubiquitous paper clip worked OK, but was a little aggresive in how it pushed in the retaining pins on the terminals.
* The ground, unbent, unhandled wiper blade supports also worked great and could be fashioned in minutes on the side of the grinder wheel.
The width of the tools blades need to be a little less than 1.5mm. The thickness of the wiper blade support is 0.8mm which is exactly what we want.
Supposedly, a ground down pair of Swiss Army Knife tweezers work great too. That would make sense to me based on my experience.
Here's a side view of my homeboy tool:
Here's a closeup of the tip:
Filing the inside of the points makes it work just a bit better.
First pull off the connector. Almost all of our connectors have "secondary barriers" and many of them are purple like the one here.
Here's a pic with the barrier disengaged:
Remove it by pressing with an awl or a small screwdriver where the red arrow is pointing. It does not take much pressure at all.
Remove it completely before trying to remove any terminals. Also, remember which surface of it is facing up.
Here's the disassembled connector:
Remove terminal for the wire you want to work on. Push the tool in firmly but slowly and hopefully you will feel or hear a little click:
Now you should be able to pull the wire out from the other side of the connector. Pull slowly and if it just doesn't want to budge, try removing and reinserting your extractor tool.
For wires in the engine compartment, there are little tiny blue weather seals. Just pull the old one off the old wire and put it on the new wire the same way.
Then, put on at least one piece of of 3/16X1.5" shrink tubing. I used two... A little peice of tape to keep it all from sliding off doesn't hurt:
Splice in the new wire using the soldering instructions above.
[Note, if you're not into soldering, you can use crimp connectors with heat shrink wraps as the dealer uses. There are plenty of posts on that.]
Let the connection cool.
Slide the first piece of shrink tubing over the connection and shrink it with the low setting on the heat gun. Take it slow...
Let that cool and slide on the second piece of shrink tubing and shrink that.
Now time to put it all together...
Pull the weather seal plug back a bit so you can grab the wire about 1" behind the terminal. Slowly but firmly, push the terminal into the hole in the connector being careful to maintain the correct axial orientation. You will hear a click when it's in.
When all the terminals are in, reinsert the purple secondary barrier.
For each wire, push the weather seal plug into the hole with your fingers:
Then, using a small -- not too sharp -- screwdriver, push it in some more so it's at least all the way in the hole in the connector.
Now, plug the connector back in and make sure the lights still work...