Well, even with the bulbs out, you still have loads [grip warmers, etc] and then their is the stator itself. If you feel you have a 12v shorted to ground, you would have to remove ALL loads. If you had a short [12v to ground], you would most likely have blown fuses, melted wires , and smoke. Nothing you have said indicates you do. at least at this point.
May be difficult finding a service manual with a wiring diagram due to the age of sled, that's what you really need. Problems like this are often beyond the realm of what forums can do, unfortunatly. Just keep us informed of your testing and the results, and we will try to do the best we can.
I'm wondering, to rule out a 12volt short to ground if you insist you have one, is to power up all your accessories [bulbs, heated hand grips,etc.] with a battery and hooked up with a fuse [in case you do have a short, fuse will blow instead of wires smoking], with the sled engine OFF. If you can power up your accessories with a fused 12 volt battery with the sled engine off, that would rule out a short. Just like turning on your key on your car to get the lights to come on-engine off. Just thinking out loud here....