A steering wheel actuator is attached to a steering wheel column. The steering wheel actuator includes a gear assembly for turning a steering wheel on the steering wheel column, a motor for rotating the gear assembly, and an enclosure. A control system in the enclosure controls the motor to automatically steer the vehicle. The control system may receive global navigation satellite system (GNSS) signals from a GNSS antenna and GNSS receiver located in the enclosure and automatically steer the vehicle based on the GNSS signals. The control system also may receive inertial measurement unit (IMU) signals from an IMU located in the enclosure and automatically steer the vehicle based on the IMU signals. The control system also may receive user input signals from a user interface located on the enclosure and automatically steer the vehicle based on the user input signals.