On a ride, during a low speed maneuver on a parking lot, the sidecar starts to twitch in small jerks then stops, everything is switched off at the dashboard, even the clock.
You know, in these cases, a multitude of things go through the head at high speed...
And I stopped on the vision of the white and red wire with a lug which feeds the fuse box of the battery and which under the fuse box, all the current which feeds the motorcycle goes away, ditto for the recharging of the battery.
Indeed, the lug had taken some play and had partially disconnected, a slight tightening with the clamp and it started again.
A business smoothly conducted under the amazed look of my wife who appreciated the speed and my "phlegm".
Back home, I replaced all the white and red wire, which was well brittle and slightly oxidized in places, I had the lugs that went well, and I fixed it on the + of the starter power switch instead of it being soldered on the battery wire, which, on Mimile is in the trunk.

Good find. I doubt I would've had the presence of mind to find that in that situation.

Excellent!

Good knowledge. That red/white wire that runs under the J-Box is pretty critical to everything running normally.
On both of mine I have had to replace the connector there due to corrosion. Likewise for the alternator to battery connector.

In fact, I wonder why there is this connector, I redone the entire wire with this connector, but I think I will redo another without, to avoid problems.

That White/Red wire is the main power feed for all of the motorcycle except for the starter relay/motor.
When it disconnects, nothing works. It is a strange wire to connect with an unsecured connector.

I just rewired the cable, stay to mount it 

Should last longer than the original..