Hello, we recently bought a used Wav50-84 from an auction. I got it powered with new batteries, and it functions up and down fine. But when I drive it, the left steering rocker moves the wav forward and reverse very slowly, and the right potentiometer steers it from side to side. At first, I thought that there were just some wires switched but I cannot find a schematic to show all the wiring of the machine. any help would be appreciated!