Fuses are usually on the hot side so the components on the side you applied raw battery power to could have been damaged.
Had a little time to think it over and (as you have probably already surmised), here's what I think happened.
The accessories ground wire was hooked up to battery +.
The accessory's hot wire was then hooked to ground --- battery neg pole or frame? Might be the issue.
So you completed the circuit backwards. Now what happens???
The full on battery power goes up the ground wire of the accessory. There is no fuse or resistor on the power that is supposed to be outgoing from the accessory. You got max amperage from the battery to something that draws 15 amps or perhaps much less.
Next, the 100% battery amperage runs through the accessory probably cooking it. The resistor at the incoming end
s l ow s all that power down preventing it from escaping the accessory which might have actually been a good thing in thais case---but I don't think so.
...because the fuse burned. There was more than 15 amps coming out so that resistor (if there is one) didn't resist it any lower than the rating of the fuse which is 15 amps.
So you had full battery amperage go in the wrong end and come out he wrong end....
Where did it go from there?
Back to battery neg terminal? This is same as holding + and - of jumper cables together. The battery will probably self destruct. Obviously not because you have power in at least some of your instrument displays.
Was the positive wire (you thought was negative) grounded to the frame? That would probably be a lot better than straight back to the battery.
and you changed the battery so that be irrelevant. provided it has 12 v or more after a charge (I just charged my Shorai for 12 hours and it was at 12.1v after installed) the bike should start.
Unless damage was done to other circuits from the reverse polarity overload.
High amperage requires a thick wire. Small wires will act just like a fuse when too much power goes through them. They will burn through and break the circuit. Since you had other wires get burned insulation, it's possible the current also went up the to where and to what effect, we do not yet know.
Sounds like you got you a winter project Seno. We'll be around. ...at least I'm good moral support but rudy up there knows his electricity a lot better. Nightmare will probably have some good advice too. don't give up.
08 MIDNIGHT SAPPHIRE BLUE ZX-14 Now Deceased, will be resurected
2024 ZX-14R bran friggin NEW!