Picked up a 2009 Streetglide and it has this thing on the upper right hand side of the inner fairing. Has 4 contacts where something apparently slides into and a 1/8 inch inlet on the side for what I can only assume is for an audio cable. There are no numbers on the unit but it does have the Harley emblem on it. I've searched and can't find any information or anything that looks like it.

 

Im not sure but it looks like a satellite radio antenna?

 

It looks like something plugs into it like a phone dock or sat radio maybe? Can you follow the wiring and see where it connects?

 

GPS unit ??

 

Haven't a clue! If you get stuck call by your local dealer, but we'll do our best!

 

It's the faring mount for the 1st generation Road Tech Conquest GPS. There was also a matching mount for the left side for a Radar detector.
I still have mine Has not been used in years since I upgraded to a Road Tech 660. Just got it out and turned it on still had a charge. Interested make me a offer by PM

 

Id guess trailer brake controller lol

 

I was told by the local Harley dealership today that it was a radar detector mount. Like you said though, the one I saw in the picture appeared to be mounted on the left side of the fairing and this one is on the right.

 

Found this pic of the Radar And GPS mounts here on HD Forums.
I have the GPS that I Would let go real cheap Also have the car mount if I can find it.

 

It's surprising to find a person at the dealership that could almost identify the mount, only to be wrong, just seems they knew about the items they should have known what mounted on which side. It is (as vz ha already answered) the GPS mount, not the radar mount, but you already know this now too. I know if it were me I would take up VZ on the offer, because your not just going to find the items, unless you plan on removing it and repairing the inner fairing. I know that I actually tried to purchase the radar mount and detector back about three or so years ago, and while I could come up with a couple then, I did not buy them, because they were very much loved by the people selling them.