For some unknown reason, (which concerns me a bit) the light on the switch started working again and the defroster is now fine.

I am still not sure why I did not have any voltage at the defroster fuse (as measured with the fuse removed). I did not measure it again yet (3" of snow so far this morning) but I am assuming that the voltage is now also back.

I'll wait to further diagnose the problem if/when it happens again.

for now all is fine.

Thanks

Phil