I’ve owned this for a few years and have had zero problems until now. Steering goes full left when the drive trigger is pulled. Thought it was a stuck joystick switch. Just replaced the entire joystick and have the same problem. Dug into it more and it is definitely an electrical problem. It uses +\- data to communicate between the controls and the ECU. The ECU left steering output goes to +12V as soon as the drive trigger is pulled. The problem is either with the platform control board or the ECU. Both options are a $1000 + fix. Looking for a way to verify what part is bad.
have you followed the wire from the joystick to the control board and the the ECU to make sure the wire hasn't rubbed itself a ground. If this circuit is Ground side switched or ground side controlled it would have 12volts on it and when the you hit the left the ECU would close the circuit to a ground to turn the wheels. Maybe the left control wire has rubbed it self to a ground somewhere?