For the motor I think replacing the cable that comes out of it is the next step .(is this the harness ?) It is the only original wire between the battery and the motor.
Perhaps running the two batteries parallel will help the battery to restart doing it's job.
Hi Steve,
Sunday night I went to plug in the chargers into my pair of batteries and ended up sticking one in at a bad angle . I shorted the plug with a big spark. The charge port now needs to be replaced as it melted pretty bad. Since I have not had time to change it and still want to ride to work I am still using it. I am leaving both batteries turned on and both are wired parralel to the controller. For the last 3 or four nights I have only been using one charger plugged into the good port on one battery and the second battery is being charged through the parralel conection in the front. This has worked fine and both batteries end up being charged fine.
The reason I mention this is if you could parralel your batteries in the front and try charging them both with one charger plugged into the working battery. Leave it over night and then check the voltage on both batteries when the charger is done. I would use the original charger plugged into the original battery for this test. If the second battery gets a good test take it for a good ride and see how it works. it may be the bms preventing it from taking a charge and this could be a way of testing it.
Of course this may harm other cells if one is dead. but the fact the chargers will not turn on when the battery is at 40 volts seems charging related rather then cell related.
Anyway take this with a grain of salt as my methods are a little brutal at times and usually when I think I know somthing it is quickly pointed out that I am wrong
Gary