I was online looking for parts to my cart and noticed your problem posted. Mine did exactly the same thing.
It has a controller that goes from the accellerator that ends with a brass control that gets corroded and sometime you just have to remove it and shine it up. It works similiarly to a brush on a motor.
Mine was not going at all and I have found that when it gets dirty, you can sometime "STOMP'' on the accellerator and it gets a charge through it. It still needs to be cleaned but it will run fine for awhile.
I also found that you could get it rolling downhill (the first thing I tried) and hit the accellerator and it started going. No more problems until the following day. That's when I found the controller with burn spots on it.
Now, after you try this, I will check back on the board and see if you had any luck.
Stomp it good and hard, now.
