Sorry - Another Butt-heat question

[washburn]

Following an excellent guide on how to track down seat heat problems, I
am a bit stuck and though perhaps someone could help before digging
further:

The voltage and resistance testing I did pointed to a bad wire according
to the guide, as is usually the case.  No such luck that I can see upon
dis-assembly.  Wires are solidly attached on teh seat bottom and back,
and there is no scorching of the pad materials.  Element wires that I
could see looked O.K. too.  Hmmmmmm.  The relays click predictably once
when switched on.  The fuse is O.K.  (I checked it and horn works)  

The guide mentioned that the resistor type "thermostat" should be
checked.  The tiny "bud" buried in the cushion.  It did not,
unfortunately, say how you know it is bad and what to do if it is.  Is
this a special Audi only part, or is it a Radio Shack kind of part?  Any
help would be greatly appreciated, it's getting cold up here!

Pat Washburn
Wausau, WI
88 5kcstq Wagon (stiff springs, shocks, and bushing on the
way....looking at boost after that!)