[wmws]

I don’t know about Tom Toms but Germans run on 5 volts. The adapter will cut the volts down from 12 or 6 down to 5. Assuming you have a standard Model A with positive ground you have to be careful about the polarity. Reverse the wires + to - and - to +. If your adapter case has metal around it be careful because now it is hot and will short to ground. Just insulate it somehow with tape or something non conductive.