XT charging & 40% brightness issues

[JS_racer]

I may consider another mount idea, using the USB, as when I connect this cable it does charge.

Right.
I had the same set of issues on my bike ST1300 (Pan European). I also got the 40% issue on a rented BMW in Spain and my old backup Nuvi 1450 saved my day.
At home, my solution was connecting the nav via USB cable to a USB 2.0 plug wired to an ignition vires. No power loss issues anymore.

the output of the usb adapter needs to be 2.0a or more, then no issue..
I use it in the car on a dual 2.4a adapter, to usb cable. full charges the gps running up to 17 hours with no issue.
tried it on the bike with a 1a, dim screen after X time , swapped adapter on the bike to a 2a, perfect.

[Peobody]

tried it on the bike with a 1a, dim screen after X time , swapped adapter on the bike to a 2a, perfect.

Interesting. I had this problem while using a dual 2.4 amp cigarette lighter adapter on my Goldwing. I had to wire the Garmin mount. I also had the same problem when trying to use the XT in my car (2.1 amp cigarette lighter adapter). I have since learned about charging (power only) cables and have purchased one for the car but have not tested it.