Repairing Your Car’s Electrical Connectors Is a Solid Start to DIY Wiring

It’s easy to break electrical connectors and luckily it isn’t that scary to replace them either.

byApr 29, 2022 12:33 PM
A 2010 Volkswagen GTI sits beneath a sunbeam. Concrete support beams washed with rust in the background.
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It seems that I am finally reaping what I sowed after investing in a 2010 Volkswagen (VW) GTI two years ago. Most other people would put the money in some stock account or in a retirement fund, but not me. I bought a big dumb German paperweight that has suddenly and ferociously started misfiring for no good reason.

What I mean by reaping what I sowed is that I’ve driven this car viciously hard for a solid two years and 50,000 miles. I have had mostly trouble-free operation, save for plenty of preventative maintenance and some periods of mild brokenness. The car has never left me stranded or worried about calling a tow truck until just a few weeks ago, when this mysterious cylinder two misfire appeared.

I was about 40 miles from home when my car mysteriously dropped cylinder two. My immediate reaction was to find an exit, roll into a safe parking lot, and swap some ignition coils around. Weirdly, my misfire was solved by swapping cylinder two and three, but the misfire didn’t move with the coil. It subsided quickly, so I seized my chance to get home. This incident was especially strange because I had just installed fresh ignition coils because of a previous cylinder two misfire incident.

Though I didn’t suspect it at the time, there could be two reasons for this behavior. One, my ignition coil connectors aren’t seating properly, which is likely because mine has broken locking tabs. Option two, the one I didn’t consider, is a fuel injector failure. Normally, injectors fail abruptly and don’t fix themselves so I had no reason to suspect it. I set about repairing and repinning my ignition coil connectors.

Unfortunately, damaging electrical connectors can be fairly easy, especially with older cars. Age, heat, and previous repairs weaken the plastics to the point of croissant-like brittleness. At a certain point, any interaction with the connector will cause it to break, usually at the locking tab that prevents the connector from vibrating off of its terminal. Pieces of the connector can also break off and prevent a secure connection. Most of the time, some clever zip tie work can solve this problem, but it’s best to have a properly working connector.

I went to Deutsche Auto Parts and ordered a set of four genuine VW connectors and the depinning tool to push the wire out of the connector. From there, the process is fairly simple.

You have to unplug the connector from its place and locate its primary locking tabs for the pins and don’t forget to disconnect the battery. For VWs, a flathead screwdriver turned gently sideways within the tab will unlock it or break it. Most connectors will have one or two of these locking tabs that keep the pins at the proper depth within the connector. In the case of my VW, there is a pink slip tab that can be easily removed with a pick or a small screwdriver. Most other types of connectors will require a small pick and some gentle prising of tiny tabs. Sometimes, you might not even need a depinning tool, and the pin will release easily once the locks are removed. 

Once I removed the pink tab, I could use the depinning tool to push the pin out of the connector. It can be something of a pain because of the final metal locks on the pins themselves, but perseverance pays. Make sure to note the location of each wire in the connector and write it down or take pictures. Alternatively, you can break the connector into pieces to retrieve the pins, just be careful to not damage the pins. I used a set of hose pliers that worked as pincers to precisely fracture the scabrous plastic. It’s messy but it worked well for me as a last-ditch option. 

I took photos of the location of each wire and I also swapped wires over one at a time to avoid any errors, taking care to not fully seat the pins until I had all four oriented in the new connector. This gave me the room to insert the other pins and seat them properly once installed. Just push the pins in until they click. I used a straight pick to fully seat each pin. Repeat this process as many times as you need to and you have fresh, functional connectors.

There was great satisfaction in reconnecting my ignition coils and feeling a positive latch once fully seated. However, there was a lot less satisfaction when my misfire stubbornly remained.

Next time, we’re digging into swapping and preparing direct fuel injectors.

Got a tip or question for the author? Contact him directly: christopher.rosales@recurrent.io.