Earth points

[A TR7 16V]

I have an earth point on the right hand mounting of the coil that's not actually electrically connected to the body. Since it provides the earth point for the main and dipped headlights, that's an issue. A previous owner's connected it the the point where the main braid from the battery connects to the body, but its a manky bit of wire that's obviously overheated at some time and the insulation's softened. 

The question is, should there be a separate connection between these two points on the body, or should the one by the coil alone be how the lights earth?

Graham

[A TR7 16V]

I've fitted a strap from the battery to this earth point by the coil. But I'm still confused:

There're thickish wires in the loom feeding the main and dip beams, but the earth returns in the loom are much thinner. So, that must mean the returns from the dips and mains must be through something other than the loom wiring, or that would be at least as thick a wire as the feeds.

But, can that work through the bonnet hinges?

Graham