How to Replace Broken Wire-Harness Clips or Connectors on Audis and VWs
Broken Wire Harness Connectors
In all my DIY's I always stress the need to be gentle when removing these clips. And sure enough, when I went to take pictures for my temp sensor article, I got a little too eager and broke the clip right off.
I had also broken one of the coil clips many years ago, but the wire harness stayed on just fine so I never worried about it. This time I was not so lucky.
(If you do have a broken clip on the coil connection. and do not feel like spending $30 and doing this repair, you can always use a zip tie to keep it in place).
This DIY covers how to replace the connection housings from the wires to the sensor, or coil, or whatever part you happened to break off the connection to. The part number should be the same for MKIV and the newer MKV Jetta and GTI models as well as Audis and Passats. But, as always, make sure you verify the part number with your local dealership before you buy the part.
I will be doing the repair here on a temperature sensor plug, but it will be the same operation for the other connections as well. If I ever break down and buy a new coil connection, I will upload pictures for that connector too.
Tools Needed for the Job
This DIY can be done with household items. If you plan on going all out, you can buy a specialty tool called a "Terminal Release Tool" for $70 to $110 that has the same effect as using a standard paper clip.
- A paper clip
- Hammer or vise grips
- Needle-nose pliers (optional)
- Small flathead screwdriver
- Replacement part
Depending on which clip you broke, the most common housings are part numbers 4B0-973-724 and 4B0-973-712.
- 4B0-973-724 is the connection for the Mass Air Flow Sensor, coils, and the like, and runs around $30 each from the local dealership.
- 4B0-973-712 is the smaller plug used for the Temperature sensor, AIT sensor, Throttle Body and like connections. That part will run about $12 at the dealership.
These plugs can also be ordered online from ECS Tuning for about $18 and $9.
Lets Get MacGyver on this B!!
Yeah, welcome back to the '80s. If you decided against the hundred-dollar tool, then it's time to make your own out of a paper clip.
For the larger connections (MAF or coil), use a large paper clip; for the smaller connections (temp sensor), use a small paper clip. Start by flattening the ends with a hammer or vise grips. Then curve the clip around till the two ends are a few mm apart. Look at the "tools" picture above for reference. Yes, that's it. So save your pen and rubber band for another day, my fellow MacGyver fans.
On With the Procedure
To be honest, this is a quick and simple DIY, but it is a pain in the blank the first time you do it. If you are changing the larger (MAF or coil) connection, it should be a little easier.
Step 1. The first thing you want to do is remove the pink/purple clip inside of the harness. It slides out very easily, so use very little pressure. It also helps to place some newspaper under whatever connector you're working on, so you don't drop these little pieces into the engine bay.
Step 2. The black hose that covers all the wires has a little clamp on it to keep it tight. It really helps later on to take this off and pull out the wires. You can remove it easily with your fingernail or a small screwdriver. See below.
Step 3. Take your homemade tool and wedge it in on both sides of the connection pin (see below). The trick is to get it in deep enough to bend down the little tabs that are holding it in place. I'd estimate about a half centimeter in.
Step 4. With your tool in place, pull on the wire from the back side till it releases. It will take a little persuasion, but don't rip it out with all your force (see diagram below for a better example of how the wire connections look). You're trying to release it without breaking off the tabs. You can also use your needle-nose pliers to get a good elongated grip on the wire.
The tabs or prongs are in there to hold the wire in place. To release the wire from the harness, you push or bend these tabs down slightly. These little tabs can be carefully opened back up with a penknife or small Swiss army knife before they are re-inserted into the new harness. Don't bend them too much, as they are thin metal, and break easily like everything else VW/Audi makes. If you do break the tab off of one side, don't be overly concerned; it will still stay in place once inserted into the harness.
Step 5. Once all the wires have been released (two or four, depending on the plug) you can bend back the tabs slightly, so the wire will hold firm in your new connector. You can use a penknife to slightly bend them out. The last photo shows the tabs, although the resolution is not that great.
Step 6. Push the pins back into your new plug with your fingers, or with pliers if that helps. Make sure you write down which color wires come out of each hole. The plug harness will be labeled with 1, 2, 3, and 4.
Wire Harness Diagrams
These are some drawings that should help with understanding the pin connector and keeping the wires in proper order.
For the temperature sensor the colors are:
- Brown with white stripe
- Green with yellow stripe
- Brown with blue stripe
Even on my own car I have different colors going to the 1,2,3,4 on the coil, so make sure you write down what color is going to what connection before you pull out the wires.
- Red, blue/white
- Brown/tan, black/red
- Blue, dark brown/yellow