Hyster,

The steer sensor in the steer column may have failed. Remove steer column cover, turn lift on and move steer wheel. Look for led light to come on at sensor. If the light goes off at any point, replace sensor. Should the light not come on, unplug the connector and check for battery voltage across 11D and 13X. If you have battery voltage replace sensor. Also check fuses 4 and 7. The steer motor cannot be rebuilt. The controller and motor are one assembly. Good Luck