Hi and
to GM forums.
I would definetly check inside the motor for more freyed cables.
I get the feeling there is still some problem with the freyed cables I have experienced similar problem with freyed cables on one of my controllers way back when.
Please resist the desire to ride the bike and test it until your absolutley sure all cables have been isolated from each other. Use heat shrink or replace the wires with good ones with adequate insulation.
Please let us know how you get on..