Check the relief valve setting in the steering pump, its built in. Should be 1200-1250psi I think, measure at the pressure outlet from the pump or before it goes into the SCU (orbitrol). If the steer pump relief valve isn't unloading it will overload the motor. Also i'd recommend putting a clamp meter on the motor cables and see what current its actually drawing as well as checking the voltage at the motor compared to the battery.