Hi Adamsavage79
Sorry I don't get the whole picture.... you got your throttle plugged in in the wrong plug, but how, my controller has only one of this 3 plug connectors, yours has more?
Some pin get pushed in, in your throttle cable or in the other one? If this connector was originally free (not connected to anything) and only one pin get pushed in and this pin is not contacting something else, then this is not the source of your error.
After you plug your battery pack and controller, the voltage gets pulled down from 53V to 2.3V ?
That is a heavy sort circuit, then something is on fire (ok ok bad joke) I think you meant 52.3V some voltage drop can occur when your controller is plugged in, but 1V is to much...
I think you have some bad or out of balance cell(s) in your battery pack and the
BMS is triggering the under voltage protection.
With no load the wheel is spinning that's ok the half dead or empty cell can deliver some current without tripping the under voltage protection. Try to apply some force to the wheel to slow it down, then your current will go up, bad cell voltage down and
BMS under voltage gets triggered.
I would try to charge the cells separately to see if there are some cells under charged.