looks like the can bus socket for plugging the sat nav in,
take it all the clocks/lights are working properly?
have you had the bike since new? prev owner may have routed the cable up and round from the headstock?
does look similar shaped to the canbus socket but they dont have the green piece in the middle - mine doesnt anyway

Thanks for the replies... I'll do a bit of investigating .....It'd be a good place to power the FPC work around from![]()
Fiddling about in the screen area, disturbed this ... then looked for somewhere to plug it back in... nothing's obvious
its cable tied along the screen strut..
That plug is the Sat Nav power feed for a Tom Tom Rider. Check for the extra cabling at the battery![]()

Thanks chaps
I'll just forget I've found it then.... no good for the 2650and its installed already
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If it is the TomTom lead (seems likely) it must be powered somehow. Is it still live?
If it is, you could use it for powering something else, if your Garmin is already powered.
If nothing else, cap or tape the ends off. You probably don't want water and grot going down it.