Just posting this based on the experience of a friend which may help someone else. The electric door locks quit working on his caravan and after multiple trips to the dealer they were told that the part they needed was no longer available. So they just learned to live without them. Then one day the Caravan would not start. It turns out they had a bad cell in the battery and needed a new one. After the new battery was installed, the door locks worked. I imagine it merely allowed some control electronics to reset when the power supply was cut off by unhooking the battery. It is certainly a cheap and easy way worth trying first for a problem.