Metal plate is for heatsink purposes...
There is no reason to actually go INTO Thr controller at this point.
You could cut the wires at some midpoint and use the test meter on either side of the wires.
check what ebikes.ca says could be the problem and troubleshooting technics and if there is a problem on either side (controller or motor), or in the wires, you have two choices..
1.) take apart the motor and replace a possibly faulty hall sensor or fix the broken wire(s) that might be the issue.
2.) send it back to ebikes.ca and have them fix it.
Does the controller have sensorless control?
If so, then all you have to do is start pedaling until the controller reads the back emf from the phase wires and the motor should start running.
If not, then either get a sensorless controller or either of the two things I just mentioned you could do.
First question: Has it ever ran?
The most common problem I've read about hall sensors is the connector. Pull it apart and make sure all the pins are locked in place. Sometimes if the pin isn't locked in place when you push the connector together it'll push the pin back into the housing and not make good contact. When you pull it apart there sometimes is enough pull the partially pull the pin out and when you look at it, it looks almost ok. The socket could have a bad crimp with a partially crushed socket. It won't allow the pin in. I know this basic stuff but so many times I've failed to eliminate basic stuff and assumed the worst right off the bat.