You’re working on your bike, you’ve pulled your gas tank off, removed your airbox, and taken off your throttle bodies. You’ve cleaned them all and now you’re ready to put them back together, now which wire connects to which? You’ve got 7 different connectors and now you have to make sure all of them are connected to the proper end, which isn’t too difficult because normally they use different types of plugs on the connectors so you can’t plug them in incorrectly.
But the bigger issue is what if you forget one? What if you put them all back together again and then go to fire the bike up and you realize you didn’t connect the upper airbox? Or you didn’t connect the throttle bodies? I can speak from experience haha because I have had both of those issues and more. That is also only if you are using a Kit harness, if you are using the OEM wiring harness there are a bunch of connectors for headlights and turn signals and things that you do not use and never will so it is even easier to not connect something.
One easy way to remember which wire goes to which is to get some different colored electrical tape and then tape the male and female end together so you know purple goes with purple and red goes with red. It also is a bright color so then in the jumble of cables inside your bike you can easily spot the different pieces of tape. One of the things I have found recently is that I was given a gift of some electrical marking tape (super small ~5mm wide tape with a number repeated on it) I was able to go through and mark all of our Translogic system plugs to label which plug goes to which number coil pack. I also went through and labeled each of our handlebar switches with our On/Off switch being labeled 1, with Pit Lane Speed limiter being 2, and Fuel Map being 3.
Here is a link to the tape from Amazon and Home Depot:
https://www.homedepot.com/p/ScotchCode-0-9-Wire-Marker-Tape-Dispenser-STD-0-9X/207007351