As I suspected; the plug has a built in transformer to supply 5V to the cradle. I have a Tom Tom Rider 2 and the cradle has the transformer built in so it's leads can be wired directly to the bike's 12V electrical system. You cannot simply cut off the plug.

Your best bet would be to open up the plug, solder two wires to the input side of the transformer and reseal it sans the actual plug contacts. You will then be able to mount the remains of the plug/transformer remotely and connect up to the spare connector behind the dash.

If you don't fancy adapting your plug in this way, you could either source a 12V-5V DC transformer, or maybe try and get hold of another Tom Tom Rider 1 plug to modify.

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