I think someone must had had them apart.As they are an electro-mechanical device I would image some kind of small deflector coil.Being stuck they may well be serviceable with some penetrating oil like WD40 and then lubricating with Isopropanol Electrical switch cleaner.You can get this from Hi-fi shops/Radio shack(USA) Maplins Electronics shops(UK).
Common brand over here is Servisol,
http://tinyurl.com/5r33kw
This is a must have anyway for bikes/cars and Ipods etc for keeping sockets and connectors in good condition so it never goes to waste.
Remember also they are 7v so never test them on a 12v battery!!
If you need a 7v regulator for the bike you can make one cheap,
http://myweb.tiscali.co.uk/cxism/AuxVR01.html
The fuse and the capacitor are optional
