How can I turn on the lights on C-class? May 02, 2020 01:24 Press and hold + button for 3 seconds. Related articles Tire Pressure: C-Class Battery Removal: C-Class My X-class doesn't turn on, what should I do? What's the max speed of Ariel Rider C-Class Commuter Ebike? Comments 0 comments Please sign in to leave a comment.