FD radio harness mystery wires
 

I've searched and haven't found an answer to my question. So I've owned my car for about 10 years and not once did I ever use the basic radio cause it was never hooked up properly. I've been using mp3 and Pandora for tunes.
The stock plugs we're cut so it was fun looking over the fsm diagrams. I finally got to see my antenna function for the first time tonight! I need to get a double ended antenna adapter now.
Ok so here is the question. I'm trying to get my center speaker to work cause I'm already in there and don't want to go back. I wired my remote turn on to the green/black wire and was able to power on the center amp. Thing is I get some low annoying electric sound from the center speaker now with the car on and volume down all the way. With music going I don't hear it and the speaker works​. I have three wires left over in the harness that have me wondering where they go and what they do. I have a solid gray which from the looks of it came from the stock stereo and goes to the center amp. Where or what does this wire do? I also have a red/black wire 1E from the fsm radio connection plug and a red/green wire 1F from the same plug. The diagram does not show these two wires. So I'm trying to find out what this gray, red/green and red/black wire go? Any input would be appreciated. Thanks!