I tried wiring in a cigarette adapter so I could plug in a cell phone charger. I failed. It kept burning up the circuitry in the charger but didn't blow any 5A fuses.
Why?
What have you guys done to wire in accessories?
Don't know what might be wrong there, but I installed a Powerlet adapter on my Monster years ago and it's been quite useful. Follow the installation instructions and you'll be good to go:
http://www.powerlet.com/product/ducati-monster-kits/135 (http://www.powerlet.com/product/ducati-monster-kits/135)
That's a BMW-style adapter and you can get plugs and accessories from Powerlet.