So whilst it’s not the end of the world to solder a contact (meant to be crimped), you should crimp these where possible. For this reason you’ll seldom find anything other than crimped contacts on cars. This creates a common point of failure, especially for wires that get regular flexing or vibration. One of the problems with soldering our friendly old KK contact is that the solder inevitably wicks up the wire and this makes for a brittle junction around the top of the contact. Whilst crimping is faster, it also creates a more reliable, consistent connection.

I must confess to thinking that crimping was mainly about speed for volume production and that crimping was an expensive luxury. Why bother to crimp? On the face of it, it seems barking mad – squeezing some metal around a wire and expecting it to hold fast and create a good electrical contact. This is a very common practice amongst Makers and one that I used myself on many occasions. It’s worth at this point, taking a moment to consider the other option, which of course is to solder the crimp contacts.

As they hadn’t, there followed a discussion on the options which basically fell into two camps: buy the genuine Molex crimp tool ( 63811-8200) for the eye-watering price of £240, or go for a cheaper more generic crimp tool. These leads were terminated on one end by the common 0.1″ molex KK connectors and I enquired whether they had a crimp tool for these. I was recently discussing some equipment repairs and refurbishments with a new sub-contractor and the subject of replacing a number of leads came up.

Crimp tool for molex kk 254