Monday, May 14, 2012

Do your 12v electrical work properly.

If you've ever dabbled in 12v electrics in your car, you've probably come across one of the enemies of electrical systems - the spiteful little piece of metal and plastic known as the scotchlock connector.
These things are marketed as the saviour of wiring for people who like to do their own modifications. The idea is simple. If you want to splice two wires together, and one of them is an existing wire (like a +12v line, you can use one of these connectors. One side snaps over the existing wire, and the new wire goes into the other side. When you crimp the metal piece it pierces the insulation on both wires and makes an electrical connection. Clip the plastic snap closed and you're done, right? Well - for now. But later on, that connection will fail in all manner of creative ways and you'll be left with nothing but trouble which, for the most part, will be very hard to track down. Scotchlock connectors need to burn in hell.
If you're going to do your own electrical work in your car, do it properly. Use bullet connectors or crimp connectors if you're cutting and splicing wiring. They're just as easy to use as scotchlocks but they're a thousand times more reliable. You need to invest in a crimp tool - looks like a pair of pliers with notches in the jaws - because pliers won't crimp the electrical connection properly. But the end result is secure wiring that won't vibrate or pull apart and won't create electrical problems further down the line. Everything from engines that won't start, to flickering lights, to fried engine management computers to non-working instruments. I've seen all these things caused by sketchy wiring from people trying to scotchlock a new radio into their car.
The attraction of Scotchlock connectors is that you don't need to cut the vehicle's original wiring to splice lines together to make a Y-connection. In reality you are cutting the wiring though, because of the metal blade inside the connector. So given that, just cut the wiring and do it properly. Take one end of the cut wiring and the new wire, and crimp them together into one end of the bullet connector, and take the other end of the cut wiring and crimp it into the other connector. Simple - that's a Y-connection. Clip the two connectors together and you're done. For connections that don't need to be taken apart again, you can use an even simpler crimp connector and just stuff two wires in one end and one in the other.
It goes without saying that any work you do on the electrical system is best done with the battery disconnected. Although if you're the type that uses scotchlock connectors, chances are you never figured out to disconnect the battery in the first place.


Paul said...

I have to laugh at this one Chris. I work for a two way radio manufacturer (public safety/utilities, not "M") and many years ago, when I was in the installation part of the business, we used to have arguments, I mean discussions, with customers as to why we used the more expensive connections (only by a few cents per connector!)instead of the push on type in your article. Some people just couldn't understand why we did.
Memories, memories :-)
Save today, pay for it tomorrow.

Micah Cameron said...

Oh gosh, I could not agree with this post more. I'm a bit of an electrical guru, and I actually enjoy fixing and modifying the wiring in my cars. As the owner of an 88 Audi, I am very familiar with the headaches poor quality wiring can cause. Crimp connectors are not good enough for me. Sure, they're a million times better than the blade type, but they still expose the strands of copper wiring to air, making corrosion possible. I always, always solder and heat-shrink my wires. It takes longer, but the end result is wiring that will, in all odds, far outlast the car.

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PJL500 said...

OK, but at least your article could have touched on the alternative to the scotchlock connector. The alternative means severing stock wiring, stripping both ends and crimping TWO sockets to the supply side of the severed wire (which may, depending on the core, require firstly crimping a pair of wires to the supply side) and then crimping a plug to the other severed line. THEN performing the actual connection you started out requiring (by crimping yet another plug to the newly added line.)
This is the actual requirement (up to 5 crimped connectors) when contemplating replacing the all-in-one scotchlock which would take all of 15 seconds to perform.
'Jus sayin'.

Chris said...

@pjl500 - the whole last part of the article talks about exactly that - bullet connectors :-)