I have a lifted 2005 Club Car Precedent 48 volt. The kids were riding it a few weeks ago and it hasn't been right since. It runs okay for about 30 seconds then loses power. I have to feather the accelerator pedal to get it to go. If I floor it, it stops. I found the coupling to the speed sensor jammed into one of the motor studs and the side of the connector that was attached to the speed sensor was damaged and burnt.
I replaced the speed sensor but still have the same problem. I have also noticed that the automatic braking no longer works. The batteries are older but I have 51.3 volts when fully charged. 
Any ideas?

Thanks!