I have a 2009 900LT as well. I installed the 12V accessory plug on mine and it works great. I'm having a problem with the batter though. Along with the accessory plug, I also installed amplified speakers, battery charge indicator and boogey lights, all directly wired to the battery. When I turn off the bike, I always make sure that everything is powered off (speakers are turned off, lights are turned off and nothing is plugged into the accessory plug). I've noticed that since installing these accessories 3 months ago, my battery seems to be dying quickly. For instance, I ride for 70+ miles one day, when I get home, the battery is fully charged and everything is turned off. I come out 3 days later and the battery is low (not quite dead, but not enough to start the bike). Then, I fully charge the battery with a battery tender, ride for 70+ miles, come home, turn everything off, let the bike sit for a week and the battery is totally dead.
Do the accessories (amplified speakers, accessory plug, lights and battery indicator) still draw juice from the battery, even when they're powered off? That's the only thing I can think of as to why the battery is dying so quickly. If so, what should I do? I found an extra lead that is only "live" when the bike is on, but when I put the meter on it, it's only a 10Amp circuit and I'm afraid that if I run the accessories off this 1 lead, I'll burn out that circuit.
Any help would be greatly appreciated, thanks.