"BATTERYS AND CABLES ARE GREAT" What is voltage on each battery and what is total pack voltage? Have you had a load test done on batterys, have you done a hydrometer test of each cell in all batterys and if so what are the readings?
Always go back to basics and start with what powers all electric golf carts. Then when sure about power sourse you can start to find problems. Its like a car out of gas, it aint going nowhere?
There could be so many things that could cause your problems that we need for you to start at the begining and go from there. Most often its battery cables or connections, but???