I've got a ciggi socket in my "dash"  for the iPhone which doubles as a satnav 
- this is on a relay that is switched by an ignition live so that I can leave things plugged in without running the battery down. 

For connecting the optimate I have another ciggi socket under the seat that goes (through an inline fuse) straight to the battery.

The newer tom tom's (and nearly all portable gadgets with a USB port these days) charge over at 5volts because that's the standard USB voltage. 

while it would be a neat solution to wire the tom tom straight to the battery, you'd have to make a voltage regulator that could reduce the 12-14 volts of a fully charged bike battery down to a steady 5. 

Much easier to wire a ciggi socket in! just remember to use an inline fuse.

                                                                                                                                                                             

Did you hard wire it ,  or fit a lighter socket ? ... this wouldn't be the cause of the electrical issue on your Bird, would it ..?                                                                                                                                                                              

good point that.....perhaps the length of smelly burnt looking wiring loom is the issue!!                                                                                                                                                                             

No Chris, I just hard wired a ciggy lighter and that worked, can't see that being the problem really but it's in expert hands anyway, trouble is the experts are baffled too! I don't think so Andy as that may be easily identifiable, we'll see eh.                                                                                                                                                                             

U got it sorted mate??                                                                                                                                                                             

http://www.amazon.co.uk/Waterproof-Cigarette-Lighter-So...mp;sr=8-12 this is what I used on for my satnav on the bike                                                                                                                                                                             

H.
I Just read your post have a look on ebay can't remember who but they make a wiring kit for the tom tom for bikes with a built in reducer and its a hard wired to the head stock then the tom tom plugs in from there, got one on my Harley its ace. as it plug in at head stock it can be removed from there to stop you having it nicked. Have a look and if you cant find it I'll check my ebay account and try and find it that way. try Tom Tom hard wire kit? Regards. Gary.                                                                                                                                                                             

Just checked Ebay type in Hardwire kits for Tom Tom, there is a English company doing it for about £12  but the yank sites about twenty pounds. Gary