Pretty standard. The CA uses 10V for their PAS input, so there needs to be a modification for most other PAS sensors to work with it. I just bought the Grin PAS sensor which made it plug and playHere they are. There are 3 wires coming out of it
If the wheel spins freely forward when not under power, then the clutch is working. It's normal to have some resistance spinning a geared motor backwards, since it's engaging/spinning both the gears and motor, but it shouldn't be where you can't turn it. If that's the case, and its not shorted phase wires or controller, then it may be something mechanical (no lube, worn bearings, etc.), which would also lead to excessive load on the controller. Does the motor spin backwards if you unplug the connectors to the controller? I would open up the motor and see what's going on. Maybe the windings are cooked.done, not sure what that does I had mine at 72- it seems slower- probably a good thing as I could have caused damage.
Now I just need to figure out why my front controller gets HOT fast. Something else that is interesting about it is that when I plugged in the learning wire it spins VERY fast and it does not turn backwards even when there is no power attached- my guess is that it is a stuck clutch if that us such a thing... not saying it is hard to turn it just does NOT turn backwards. Seems to work fine going forward under power.