Unstable script

So i made a script that check if an object is adjacent to any object and connect it to the cockpit (robot's main part) if so. But the problem is that it's very unstable : sometimes it works, sometimes it doesn't work..

I can't really figure out why..

Here's the script :

public class ObjectPlacement : MonoBehaviour {

 PlayerInteractions playerInteractionsScript;

 public bool connected = false;
 public bool connectedToCockPit = false;
 public bool grabbed = false;

 public int connectPointsCount;
 public Vector3[] connectPointsPos;

 public GameObject[] triggersDetectionGO;
 public bool[] connectPointsConnected;
 public bool[] connectPointsConnectedToCockpit;

 public LayerMask layerMask;


 public GameObject[] allPartObjects;


 void Start () {
     playerInteractionsScript = Camera.main.GetComponent<PlayerInteractions> ();
     connectPointsConnected = new bool[connectPointsCount]; 
     connectPointsConnectedToCockpit = new bool[connectPointsCount];

     allPartObjects = GameObject.FindGameObjectsWithTag ("RobotConstructionPart");
 }

 void Update () {
     for (int connectPoint = 0; connectPoint < connectPointsPos.Length; connectPoint++) {
         Debug.DrawRay(transform.position + connectPointsPos[connectPoint], connectPointsPos[connectPoint], Color.red, 1);
         RaycastHit hit;

         foreach (GameObject objectPart in allPartObjects) {
             if (objectPart.transform.position == transform.position + (connectPointsPos[connectPoint] * 2)) {
                 connectPointsConnected[connectPoint] = true;
                 connected = true;
                 if (objectPart.transform.name == "Cockpit" || objectPart.transform.GetComponent<ObjectPlacement>().connectedToCockPit) {
                     connectPointsConnectedToCockpit[connectPoint] = true;
                     connectedToCockPit = true;
                 }
             }
             else {
                 connectPointsConnected[connectPoint] = false;
                 connectPointsConnectedToCockpit[connectPoint] = false;
             }
         }
     }

     if (connectPointsConnected.All(connectPointConnected => !connectPointConnected)) {
         connected = false;
     }
     if (connectPointsConnectedToCockpit.All(connectPointConnectedToCockpit => !connectPointConnectedToCockpit)) {
         connectedToCockPit = false;
     }

     if (transform.name != "Cockpit") {
         if (connected || connectedToCockPit) {
             transform.rigidbody.constraints = RigidbodyConstraints.FreezeAll;
         } else {
             transform.rigidbody.constraints = RigidbodyConstraints.None;
         }
     } else if (transform.name == "Cockpit" && !playerInteractionsScript.hover) {
         if (connected || connectedToCockPit) {
             transform.rigidbody.constraints = RigidbodyConstraints.FreezeAll;
         } else {
             transform.rigidbody.constraints = RigidbodyConstraints.None;
         }
     }

     if (grabbed) {
         for (int connectPoint = 0; connectPoint < triggersDetectionGO.Length; connectPoint++) {
             triggersDetectionGO[connectPoint].SetActive(false);
         }
         rigidbody.useGravity = false;
     } else if (!grabbed) {
         for (int connectPoint = 0; connectPoint < triggersDetectionGO.Length; connectPoint++) {
             triggersDetectionGO[connectPoint].SetActive(true);
         }
         rigidbody.useGravity = true;
     }
 }

}

I've got an other script that place objects exacly 1 unit apart from the block i'm looking at, here is the line of code that place the object :

grabbed.transform.position = hit.collider.transform.position + (hit.collider.transform.forward / 2) ;

If you need any other precisions tell me. Thanks in advance !