"...sort of reply I'll get, Don Foster will say 'resolder it'..."

Now, now.

The glass doesn't get hot. The defroster only needs to warm it by a degree or three to eliminate condensation. So if you're evaluating by feeling for heat, you mighta fooled yourself.

"...the man that designed it into my wagon..."

Yeah, well, Sven also designed the blower motor and tailgate wiring and fuse panel. So his relay was clicked.

With the defroster on, make several voltage measurements relative to a known-good ground. One side of the grid should measure 12 volts, the other side should measure 0 volts.

If you get 12 at both side, the ground (perhaps the entire tailgate ground) is faulty.

If you get 0 volts at both sides, the wire supplying current to the grid is faulty (probably in the hinge harness).

Next, using a very sharp needle probe (maybe using a needle) measure the voltage along one stripe element in the grid, going from one side to the other. You should see a decreasing voltage as you progress across the window. If so, then the element is working. If instead, you continue to see 12 volts and then a sudden drop to 0 volts, you've just moved your needle probe across an open (break) in the element. Using a magnifying glass, examine the element for a microscopic break or tear. Often, adjacent elements will be broken in the same place—something slid down the window, tearing all the stripes.

"...he can't see out the window!"

Join all the other happy folks driving at 75 and chatting on their %#@*&% cell phones. They can't see out the window, either. But that doesn't stop them.

Don Foster (near Cape Cod, MA)