I am wanting to install a power cord for my GPS mounted to my handlebars, and I was wondering if there is a recommended place on the 06 GL1800 to attach the power cord for electrical power.
I tapped into the "under the left fairing cubby" outlet. Pulled the cubby out, soldered in a junction and ran the wiring around and under the steering. I later moved the wiring to a new location when I installed the Vent Mount for the GPS.
The Zumo cradles that I've had all had long enough cables that I ran them back to the accessory screws at the fuse panel next to the battery. These contacts are hot only when the key is on or in accessory.
I have my Garmin plugged into the 12v socket in my left cubby via USB connector. I plugged a compact USB three way splitter into the 12V plug. One for the Garmin, one for my iPhone charging, one for my Bluetooth connection. Works great.
I like the aux post in the terminal box, but the connector under the left pocket for optional OEM 12V socket will work. That latter one is on a 5A fuse, I think, so be careful if you load it up with a GPS and a cig plug that feeds a few things.
I was tempted to cut the cig plug thing off my nuvi and wire in directly, just because of the bulk if it. But the circuits to step down the 12v to 5v are in the back end of that big probe, so I couldn't without issue. I wound up soldering leads on to the probe's contacts and stuffed it in there somewhere.
Some of the zumos come with a 12v pigtail so you don't have to screw around with that. But be sure you've got one before you cut that voltage gonculator out.