Unused plug on 05 Stock Stereo???

[rounders37]

There is an unsed plug on the back of the 05 Stock stereo.... does anyone know what this is for??? It has the main plug, the attenna, and it is grounded on the side of the stereo. This unused plug is a 4 pin connection, and it is next to the attenna on the right side of the stereo. I'll try and post a pic soon.

The reason I ask is that I am getting an XM Roady 2, and I want it to be as clean an install as possible. I can take care of the power plug, I bought an additional accessory power port from radio shack, and I am going to hardwire that behind the console. But I really would like to get a direct connection to the stereo, instead of using the Wireless FM Modulator. If anyone has any ideas, please let me know. Thanks.

[zoinks]

I'm pretty sure that it's an extra lighting power source that's connected to the dimmer. It's where I tapped in for my boost gauge.

[rounders37]

That makes sense. Thanks for the response.