I had this problem about a year and a half ago. I have an AppRadio 2, with a Galaxy S5, and AppRadio 2 was on firmware version 8.17 and decided to update it to 8.30, since my phone stopped connecting a week or two ago. When I did this about a year and a half ago, the radio basically just looks for an iPhone to connect to and there no longer is an option to connect to an iPods. It just doesn't connect no matter what you do.
I downgraded from 8.30 to 8.15, and even down to 8.11 but always had problems connecting it after that. Best Buy gave me a new radio and I just stayed on 8.15. For some reason I decided to to do it again. Does anyone know of a way to get your radio to see an ipod classic 160, after updating to 8.30 or even after downgrading? I'm about to purchase an AppRadio 4 and was hoping to give this to a friend. WORKING... Thanks I appreciate any help with this issue.