Try get component in child and he change the parent why

void Start () {

		Debug.Log (gameObject.GetComponentInChildren<SpriteRenderer> ().renderer.enabled);
		var aux = gameObject.GetComponentInChildren<SpriteRenderer> ();
		aux.renderer.enabled = true;
		Debug.Log (aux.renderer.enabled);

i do this gameObject.GetComponentInChildren ().renderer.enabled = true or false and he change the parent and the child dont change.

That’s because GetComponentInChildren searches the main game object first (manual). See also this answer, for example.