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Re: 83 Ur-q rear window defogger weirdness (Solved, Thanks!)

Huw Powell writes:

 > If you are testing your wires with a high impedance meter (and measuring
 > voltages with it too) you may not catch circuits that no longer are
 > capable of carrying much current.

That was my problem precisely. I was testing wires and circuits with a 
meter that passed a very small current for checking resistance, and
the volts checks were without any load.
I hooked up a 12V fluorescent trouble light to the circuit this
morning and watched the voltage disappear.
This seemed like yet another good place for new wiring and
such. Pretty soon, I will have replaced all the wires in this thing.
Actually the new wiring was a cheat, the power was dropping off in the 
wire that supplies the switch, and the only thing before that is the
mess I call a fuse box. Rather than tear into that and probably make
something else fail, I devised a new power scheme for the rear window
defogger. I ran new power from the battery thru a new fuse holder to a
new relay to activate the circuit when the ignition is on. Then a new
wire from the relay to the defogger switch. The original wiring seems
to still be ok from the switch to the element (for now), so I left
that alone.
Thanks to Doyt, Doug, Huw, and Stephane for their suggestions.
Which reminds me that it's that time of year again.  
It's time for me to give thanks for all the help I receive via
this list, from all you helpful listers. There is really no other way
I could possibly keep my aging fleet in service. 

Thank you all!