Hi, we have a drive problem on an old hyster truck (1987), Problem started when the truck got stuck outside in a rain shower. Immediately after this, It would initially jump forward and then cut out when the accelerator was pressed. We dragged it inside and dried everything out. Now there's no movement at all, The fwd and rev contactors operate as they should but the motor will only move very very slowly when the wheels are raised off the the floor the speed does in increase and decrease with pedal movement in both directions. Hydraulics all work fine. Thanks for any help in advance.