Hey Guys

I'm curious if anyone has gone the route of making their own harness? That might sound dumb, but I'm coming from the custom/cafe conversion perspective. There's a whole lot in that harness that I wouldn't want or need when I eventually go down the road with my K100 project. I've made my own wiring harness before, but never on an injected bike.

Right now, it is serving as a great commuter for me, but at some point, it will go under the knife. I've got just about all the parts I want to do the swap, I'm just waiting until I have something else I feel good about riding everyday.

I've been making motorcycle wiring looms for the last thirty-odd years and have just started one for my K100 because the original is showing distinct signs of age-related failure. I don't know what the BMW designer was smoking that day but the OEM diagram is far more complex than it needs to be.

Effectively, there are three sub-looms in that big mess: the fuel injection circuit, the ignition circuit and the lighting circuit (including the bulb monitoring stuff, indicators and brake lights). BMW nicely place the power regulation inside the alternator so that part is just two wires.

Best thing you can do is sit down with the diagram and either a load of paper or a computer program capable of drawing electrical diagrams (my preferred approach). Separate out the fuel injection and ignition circuits, then start paring away at what's left. Ask yourself what you really need; for example, if you really wanted to you could drop the load shed function (the battery might not thank you though!), the bulb monitoring unit and the self-cancelling function without affecting safe operation of the bike. Dropping the self-cancelling function will suddenly give you access to a whole range of handlebar switches that you can't otherwise use.

I have built the ECU/FICU and ignition circuits as two independant, detachable sub-looms. I have also dropped the self-cancelling function and will be using early Honda switches on the handlebars (these are actually already fitted and hacked into the OEM loom). I am, however, keeping the BMU and the load shed function.

Did someone just say 'heresy'?

I've got a bit of a project on at the moment and have modified my 16v K100RS harness.
It's still to complex so when I've sorted fueling and a few other bits & pieces,I'm going for a Motogadget m-Unit.
It looks like a good way to simplify wiring if you only need basic operations from the build.



It's worth look.

Motorbike Mike wrote:I've got a bit of a project on at the moment and have modified my 16v K100RS harness.
It's still to complex so when I've sorted fueling and a few other bits & pieces,I'm going for a Motogadget m-Unit.
It looks like a good way to simplify wiring if you only need basic operations from the build.



It's worth look.

That looks like a very interesting product.  I want to start a new project just to have an excuse to play with one.

Motorbike Mike wrote:I've got a bit of a project on at the moment and have modified my 16v K100RS harness.
It's still to complex so when I've sorted fueling and a few other bits & pieces,I'm going for a Motogadget m-Unit.
It looks like a good way to simplify wiring if you only need basic operations from the build.



It's worth look.

I've used the m-unit before and have a few sitting on a shelf right now waiting for their turn. I love motogadget products and the guys at Revival are really awesome. I plan on using the m-unit on my K. I've also got a motoscope pro and a pair of their bar-end blinkers.

I have just gently cut into a K1100RS loom and removed the ABS portion, and some other smaller bits I don't need on my Big Block project. The plug and harness I cut out was as thick as my arm (when I was twelve) and very easy to be rid of. I've saved the bike another two pounds of unneeded weight.

Now I can make up for it by bellying up to the Sunday-morning-all-you-can-eat buffet table an extra go.

Good on you, desperado, for trying out motogadget M-unit. I hope it works and you can detail your experience here.

Shoganai on Motobrick deconstructed a K1100 harness and chronicled a reconstruction of the wiring loom from the remnants.  I don't know if she ever finished the job though. Linky below:

http://www.motobrick.com/index.php/topic,5263.0.html