Nav 6 mount wiring.

A friend has a Nav 6 and 2 bikes, to save buying yet another GPS he wants to fit a BMW mount to a non BMW bike. He wants to get a 4 button mount for ease of us but they all come with a loom for direct connection to a BM, so does anyone know which wires are the + pos and - neg ones? as we think these are all that's needed for operation. If someone has a 4 button mount to sell let me know.

Thanks
Barny

a garmin zumo mount wired direct to the battery might be a simpler solution, it has an in line fuse.