What's this wire for?

I was under the hood of my '05 Envoy XL and found this red wire bent back and just stuck in the clip holding the wiring loom. It's between the battery and the under-hood fuse panel. I see an empty lug at the end of the panel. Is this for the trailer plug 12V power? (I have the 7-pin factory trailer plug and hitch.) I don't know if this was ever connected or if it was taken loose for some unknown reason in the past. The only problem I know the vehicle has now is the fuel gauge doesn't work. Could this be related?

Thanks!

http://img.photobucket.com/albums/v474/Sport45/100_0866.jpg

The wire is to activate your trailer plug if you use one. No connection to your fuel guage malfunction.

C.B.

I own a 2005 Envoy SLT and it has been stalling on me while driving on the highway. I saw the same wire as the photo on entry #73 and I connected it and the car stopped stalling. Is there any relation between the wire and the stalling or am I just lucky it stopped?
Thank you in advance.