Hello - I am trying to install a "Backoff XP" rear brake light flasher and need access to the rear brake wires. Anyone know best way to access the wires? If under the rear trim covers, how do i remove and which one? It is for my newly acquired 2024 BMW C400GT ... which i love so far for tooling around town. My other bike is a 2023 Ducati Multistrada Rally ... a much different beast!
Thx,
Tom
I have messed with -- tapped into, but cutting and intercepting will be the same thing -- the rear wiring on
BOTH my former '22 C 400 GT and on my current '23 C 400 GT. I'm going to assume that your '24 is built the same way, in terms of this task.
Here are my suggestions for what you need to do,
or at least the steps that I took:
1) Get a shop manual.
See my post
www.bmw-scooters.com/threads/bought-pdf-shop-manual-for-c-400-gt-on-ebay.2474/
That eBay link is still valid, at the moment:
www.ebay.com/itm/133967057090
2) See the bodywork index that I created for that shop manual.
In my post
www.bmw-scooters.com/threads/body-panel-removal-primer-and-citations-to-c-400-gt-pdf-shop-manual.3505/ I have a list, in bold font, of the index I built over time, in order for me to revisit the bodywork pages in that manual.
3) Remove the left rear trim panel.
There's a connector for the wiring for the rear lighting right inside the rear fender. I chose NOT to mess with that connector because it's tiny, hard to deal with, and out in the open, and so any reworked wiring would be exposed to the elements, including slop kicked up by the rear tire.
Instead, I chose to mess with those SAME wires, but farther "upstream," in an area more easily worked on, and which is also protected from the elements.
Unfortunately, to remove the left rear trim panel you first need to bond with the bike. And by that I mean that you first have to remove some other stuff, including a big item. Here's the overview page from the manual:
4) Splice into the necessary wires.
I could not find a wiring diagram, but using a test probe I determined which wire was which. I have a list of the functions of the various wires, by sheath color, in my C 400 GT gallery.
SUMMARY:
I was adding Skene turn-signals/running lights/brake flasher to both of my 400s. And when it came time to do the '23, after having done this with my '22, I followed the same procedure. So it worked for me.
It's certainly possible that there's an easier way to do all this, but on the other hand maybe there isn't an easier way. Also keep in mind that, on both bikes, I was also adding a Powerlet outlet through the bodywork. Doing that, in the same time frame, meant that I needed to remove the underseat storage "tub," anyway.
I have all of these steps documented in my gallery, with pics and captions, starting with
https://billanddot.com/C400GT/#S-38 and running through
https://billanddot.com/C400GT/#S-44 .
WARNING:
In
https://billanddot.com/C400GT/#S-35 through
https://billanddot.com/C400GT/#S-37 I describe how I broke the fragile switch at the back of the storage tub ... so don't do that. That was on my '22 -- I was MUCH more careful when removing and then reinstalling the tub on my '23.
Good luck on your project, and I hope some of this is useful to you.
