You can reconnect by signing back into your Google account.
Once disconnected, the files within your Mac's Google Drive folder remain on your Mac but are no longer synced with the online data in Google's cloud. Google Drive: Lets you disconnect the Google Drive folder for your Google account.The default is to have everything in the folder automatically synced, but if you prefer, you can specify only certain folders to be synced. My Mac: Allows you to specify which folders within the Google Drive folder are automatically synced to the cloud.The Google Drive Preferences window opens, displaying a three-tab interface.
