I installed a RAM mount for my Garmin 60CSx today. I had ordered a bare wire plug assembly with it, but they sent a 12V cigarette adapter instead. It was the same price, and turned out to be a good thing after all.
Plugged in the cigarette adapter, checked for pinout and voltages. The adapter is simply passing along 12V direct to the GPS -- expected, since the 60 series can take up to 32V or somesuch.
Snipped and stripped the wire, and was pleased to see red and black wires inside. Double checked the polarity anyway -- all was good. Twisted and tinned all the ends, and it was ready to go.
I have the AP-2 fusebox under the seat feeding two lines that terminate in insulated terminal blocks in the fairing; one is switched and the other always hot.
The GPS plug is connected to the always hot terminal. Two pieces of bicycle inner tube make nice overlapping connector boots, and a bit of dielectric grease should keep the moisture out. Doubled back and zip-tied for strain relief.
A touch of dielectric grease on the plug should keep the moisture out... I hope.
All done, and ready to find its way home!