txt series cart jerky w/no power

[kroy1968]

i have a 99 txt series cart that I'm attempting to get running. It is Jerky and has has no power. I finished a "frame off" cleaning and repainting and in doing so thoroughly inspected cables and connections. Batteries test good and hold up under a 10 sec load test with battery tester. I actually walked away from cart 6 months ago because i entered my busy season and didn't have time to work on it. My memory told me that troubleshooting had led to a bad controller. Well, I just installed a new 350 amp controller and it is doing the same as before. i put up on stands and pressed the pedal and it looked and sounded like it was running fine. i let go of pedal and pressed it again and wheels didn't turn! I reached down and pushed the drivers side tire and it started moving very slowly. i let go of pedal and get very slow movement. I let go of pedal again and get nothing until i push tire and it barely turns.
So, what's my problem???