Good advice everyone, thanks for the feedback.

I checked the settings on my ESC and it was set to sensor only, no Hybrid sensor/sensorless, so that might explain why the motor simply stopped when the sensor wires came unplugged. I've also replaced all the motor and battery wiring and obviously installed in a brand new sensor wire. So I'm basically at billdelong's second step.

One question for you Bill: Where can I get a good sensor tester? I see things like the Hobbywing tunalyzer and SkyRC motor analyzer... will those tell me if a sensor board on a motor is bad?