Is this a spare accessory plug? I't's near the battery on my 2006 Dyna Street Bob? EDIT ***** THIS IS NOT AN ACCESSORY PLUG**** and with the cap removed. I want to power my Tomtom Rider 2 GPS with it's provided power cord wired to the bike. I also have a thought of wiring in a cigarette lighter style power plug for my cellphone charger. Do I need to add a fuse if I wire straight off battery posts? Is there a harness from HD I should be using?