Q: My steering wheel locked up or got stiff and the battery light came on and oil light came on but battery is fine and oil is there

Depending on whether your truck came with electric power steering or hydraulic power steering, this could have been caused by failing power steering whether it be hydraulic or electric. To provide steering assistance in an electronic power steering system, an electric motor mounted to the side of the rack housing drives a ball-screw mechanism via a toothed rubber belt. The screw engages a spiral cut in the outside of the steering rack. A torque sensor attached to the pinion shaft signals a control computer when to provide assistance. There are a number of things that can fail with the electronics involved in this kind of a system.

In a hydraulic power steering system, the power steering system is driven by a belt on a pulley that is driven by the motor. Your car has a power steering pressure switch that sends a signal to the engine computer when the steering wheel is turned. In response, the engine computer commands the fuel injectors to introduce a little more fuel into the motor to help to compensate for the additional load that the power steering pump places on the motor. If something in this circuit is not working properly, the engine will not be compensated with more fuel as needed when the extra load on the engine is applied, and the engine will stumble, or stall. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.