Beth Young wrote:

> 
>Or is the grid really a bunch of resistive wires in parallel, such
>that one (or more) of the lines would work, even if the others aren't
>working?
This is right. Current "Enters" at one side of the grid, "exits" at the
other side. The grid is a conductive, and resistive foil applied to the
glass, or in the glass. If it is the latter, wires in the glass, repair
is impossible without replacing the glass. If the defroster was added by
the dealer or a PO, it s a foil decal on the glass, and can be repaired
with a conductive paint where the foil has been scratched, and the
circuit broken.

Good luck, hace fun,
CB