I have replaced the batteries in my 48 volt G19 cart. Since installing, the cart seems to be DOA. I did not charge the new batteries, but am reading 51 VDC from the negative on driver’s side to positive on the passenger side. I can hear a small whine when the accelerator is pressed from the motor after the cart sits for a couple of minutes, and then nothing. The back-up alarm will sound when in reverse until I switch the cart into the tow position and back to run and then nothing. Anybody have any ideas where to start.