I have a 2002 T/C where both controls would only run the cabin fans at high speed. After posting and reading a couple reports via google, I found and replaced the blower resistor - seems that only the dealers carry it around here (local). It was easy to drop the glove box and remove the two screws - the part was already the newer AB version as was the replacement.
I noticed that the resistors (the coils of wire) were fully in tact, there as nothing wrong with then - the thermal protection device that runs between them was the problem. Part cost about $15 and took about 15 minutes to get out and back in, took 3 hours to get the part after going to several auto-parts places and then going to the dealer :)