Wondering if anyone might know what is wrong with my ACE50 electric forklift. When you step on the accelerator the contact won't stay engaged. If you go very and I mean very lightly on the accelerator then it will stay engaged and you can move across the floor. Sometimes when you are going across the floor it will kick out too. I have already replaced all 3 of the little pots that are located in the box under the steering wheel. Don't know where to start again. Any help appreciated.