We were just discussing battery separators in another forum but not this subject. On my former Pleasure-way and my Great West Van I had and have a mechanical battery disconnect. I believe the Roadtrek uses a solenoid relay so you can conveniently shut off the battery with an accessible toggle switch. So I would imagine what you are hearing might be the solenoid. If you are talking about the auxiliary battery as I assume that indeed is a camper problem and not Mercedes Benz. If it is clicking like that is the 12V battery power also going on and off or have you checked that?
