Never had it apart but it was when assembled. (IE, open it up!)
You have nothing to loose.
I would disconnect the battery and slowly pull it apart paying close attention.
Should be pretty obvious...
Please post back with what you find..
BTW, should that switch have a broken plastic piece in it, you have to replace the entire left handlebar assembly.
You check the F/S section below or PM Skooter65 , he's parting out several bikes..
Since everything else worked, it passed safety. I can engage the hazard if I bash in the button and pull it out with pliers, so they said "then it works!" Haha