iPod doesn't appear in iTunes after being used as Windows hard disk I hope you can help me with my iPod Classic 6th generation 160 GB, 2007.
Few months ago I used my iPod to store my files from Windows. I had to format the iPod to use in order to save my information.

Now I want to use it to listen to my music, but I can't, because iTunes doesn't show it as a connected device. It does however, appear in Finder. Also in Windows, it can be read and written.

The format of the disk is ExFat.

I've tried to run in diagnostic mode, it seems that it is OK with values of IO. I reset many times also. Restarting the computer too.
Open Disk Utility (/Applications/Utilities/Disk Utility), click on your iPod in the sidebar. Select "Erase" from the tabs in the center. Enter a name for the disk, then from the dropdown, select any of the 'Mac OS X' options.
Click the "Erase" button in the right hand bottom corner. This will delete all your data on the iPod
Wait for it to finish formatting, and you should be good to go!