China made golf cart is heating up and running sluggish

I have 12 batteries all are 6 volt batteries, the motor was recently fixed and the ac Curtis controller was also replaced. The golf cart is running sluggish and shakes, it turns off after only 6 seconds . I just noticed that the ac motor has three thick wires that are all heating up and also so is the frame that the ac Curtis sits on . The controller is not hot, the motor is slightly warm, the wiring is hot , the batteries are not hot. Apparently the cart is turning off because it gets hot.

Did you ever found out what went wrong?