Dolphin pool cleaner won't move more then 3 feet and back 2 feet and shuts off.

by Georgia Floyd-Skaggs
(Antioch, CA U.S.)

My Dolphin Pool cleaner is not working. The cleaner moves 3 feet and backs up and moves 2 feet and shuts off. I have taken it apart and the bearings are in tack on the rashes and the belt gear is tight and secure to the races. Do I have a power supply problem? Please help! My pool is in need of a good scrubbing without me doing it!