The powre wires for this motor appear to be 24g, isn’t that pretty tiny for the potential of 5A @ 12VDC? I have no problem with replacing them with something heavier but don’t want to unless it is needed. The motors have the encoders on them and I don’t want cause any problems with them by changing wires.
The gauge is 26, which should be good up to roughly half of the stall current continuously. In general, these motors are not designed to be stalled for an extended period of time. In some sense, it might be better to have the power supply wire melt first.