Did you consider the chassis grounds? My shelby has both both rear passenger courtesy lamps grounded to the body under the panels on both sides. The door courtesy lamps are grounded to the body under the kick panels and the courtesy lamps under the dash are grounded to the dash via the bracket that is screwed to said dash. Ford used star locks on the side of the terminal that is against the chassis. They are sharp and pierced the paint/overspray that inevitably wound up on the interior sheet metal.
I made sure that the star lock was on the correct side of the terminal when I installed the engine ground from the back of the head to the firewall, as well as the battery/alternator ground that is bolted to the block.
-Keith
