I got my e-bike two years ago. When I put the motor in the forks I was a little sheepish about tightening the axle bolts. Loose bolts plus an imperfect filing job on the forks means that one day the axle came loose and started spinning. In about one second, it had twisted the wiring into a mess. That was the last time we used the bike.
I would like to use a multi-meter to check whether the motor still works. What should I look for? Is there a wiring diagram?