animation clip wont play

I have a problem with my animation Clip which is supposed to play when his health is <=0. but all it do is stop running and give me a death point which it's supposed to do. my other animation Clips work fine.
here's my code, it's in C#

 public AnimationClip dieClip;
 public AnimationClip idleClip;
 public AnimationClip runClip;
 public int moveSpeed;
 public int rotationSpeed;
 public int maxdistance;
 private bool dead;
 
 void Update () {
 
         
     if (health > 0) {
     moveSpeed = 3;
     rotationSpeed = 5;
     animation.CrossFade (runClip.name);
     Attack ();}
 
     if (Vector3.Distance (target.position, myTransform.position) < maxdistance) 
              {
         animation.CrossFade (idleClip.name);
          }
 
 private bool isdead(){
         //bool dead = false;
         if (health <= 0 && !dead) {
             moveSpeed = 0;
             rotationSpeed = 0;
             animation.CrossFade (dieClip.name);
             dead = true;
             StartCoroutine ("enemyDead");
             collider.enabled = false;
             scoreManager.kills += 1;
             scoreManager.killsCoins += 1;
                 }
             
 
         return dead;
     }
 }