Ok.. Ill make this as simple as possible..... A while back I installed a rear camera (OEM in tailgate) in my 2015 silverado LS. I had disconnected the battery while I was wiring in the camera. Since then I have not been bale to get the Onstar light on my rear view mirror to stay green. When I attempt to call Onstar it fails to connect. I checked the connections at the unit behind the screen and all is in tact. I have even taken it to the dealer (which I pretty much never do for anything) and they have told me twice now that they need to order some part. I honestly think they do not have a clue whats going on never mind ordering parts to fix it. Needless to say its been several weeks and I keep getting the run around. I called Onstar and there isn't anything they can do on their end. Does anyone have any idea what could be causing Onstar not to connect? I have seen forums on faulty antenna's and even a hidden Onstar backup battery?