Jeff,

The proximity switch that reads the target plate of the drive unit, is not working or failed. Make sure the target plate is still mounted under the drive unit. Possible issue with steer controller. Look at the inside of the drive compartment. To the left of the drive motor you should see a light. That is your prox switch. If the lift is dirty, you may need to blow it off. If you do not see a light, switch might have failed, or controller is bad. The steer motor may be causing the noise. The steer motor is on the right side of the drive motor and prox switch is directly to the left of that. Since you are hearing a high-pitched noise, remove drive motor with all wiring still connected. Turn key switch back on and see what the motor does. Good Luck