thanks for the info, after a bit of digging around i learned what that part was and the purpose it served, and i figured it was just setting itself when the power came on, but no one has been able to tell me for definite!

It may have been making that noise the whole time i have owned the car (only a week or so) and i only started noticing it after the head unit fiasco due to being paranoid i had damaged the electrics in the car somehow!