Unable to have door Slide up after pressing Ctrl to move down, Unable to find issue in my code.

I am working on getting a door to slide down in 3D application, I am able to get it to go down, but when I press the button again it doesn't go up, see what I have below:

 public class DoorOpenDevice : MonoBehaviour {
     [SerializeField]  private Vector3 dPos;
 
     private bool _open;
     private void Operate()
     {
         if (_open)
         {
             Vector3 pos = transform.position - dPos;
             transform.position = pos;
         }
         else
         {
             Vector3 pos = transform.position + dPos;
             transform.position = pos;
         }  
         _open = !_open;
     }
 }

I have the dPos set to 0, -3, 0 in the Inspector for the door, and then I have a script that is attached to the user that calls Operator, this defines when I can press "Ctrl" on my keyboard and then it drops door down, but when I press again it doesn't go up. public class DeviceOperator : MonoBehaviour { public float radius = 8.0f;

     // Use this for initialization
     void Start () {
         
     }
     
     // Update is called once per frame
     void Update () {
         if (Input.GetButtonDown("Fire1"))
         {
             Collider[] hitColliders = Physics.OverlapSphere(transform.position, radius);
             foreach(Collider hitCollider in hitColliders)
             {
                 hitCollider.SendMessage("Operate", SendMessageOptions.DontRequireReceiver);
             }
         }    
     }
 }

Any ideas or nudges in right direction will be appreciated.

Thanks.