I have had trouble with my eclipse popping when i hit the preset buttons. I unplugged the antenna and hit the buttons,no popping.Plug the antenna back up and the popping returns. I have noticed that the radio is using the antenna as a ground. I can unplug the main ground from the harness and the radio still is on.Is this normal??

 

yes it will ground through the antenna but why is the ground disconnected in the first place, did u use a harness?