looks like a pitted aluminum ***** to me.... :shock: :-#
oh i guess there is a hole in that second photo, didnt see until posting and looking a my post. :/
theres two of those small holes, easy to miss they so small, and its pretty dirty
that whole top should rotate off the light cover, on my Challenger it had a little blue cover, as said as above just ground the case to - and apply + to the wire should come on if the bulb isnt burned out!