Leave the harness in his sight, and every now and then try again. Remember, a Zon takes years to mature, and even then they only think about eating and playing. Maybe after he comes to accept everything, and a little more calm, it might happen. As a note: A zon is treated not the same as a Grey, you can slightly raise you voice to them, you can give them a firm direct command, [no yelling] and you can use the word's " Stop, No, and don't.] They don't get the hurt feelings a Grey does. Diego is a very young baby, new to life, his home, you, and to what you expect from him ..........Keep up the good work......Jayd