yup, thats the bulkhead earth, even though they look good, they may not be (speaking from experience.
also, I believe it isn't unknown for the bulkhead to loose ITS earth.
All those items also run off the same fuse/circuit IIRC, if the fuse looks ok, try twisting the pins slightly, I had a couple that didnt quite connect properly, so everything looked ok, but the fuse wasnt connecting, so no power.
Then check to see if you have power at the fusebox for that circuit, and work from there.