electrical issues with the 67 fish

Ok, I put 12 volts to the switch spade on the relay and nothing happend. I then went back to my old relay (reinstalled it)which worked before I pulled the cluster and that one was not working as well. With 12 volts on the swich spade there was obviously no voltage at the starter lead. All this seems obvious that the relay switch is bad but I am just having a hard time understanding how mine went bad and why the new one does not work as well. I am sure I will figure this out soon. You are very helpfull and I appriciate your time. Thanks again Steve