OK, figured I'd help a few people out.
I haven't seen this talked about on here yet, figured I'd share some info on how I repair the resistor pack that controls the fan speeds.
This may not be a huge deal, since the resistor packs have come way down in price the last few years, I think you can get the A/C equiped car one for $25-30 these days. It still however can be fixed for much cheaper, little over $1 in parts and 5 minutes work.
99% of the time, when you lose all speeds but high on the blower it is due to the thermal fuse blowing. On the old cars it is common for these to go once they reach a ripe old age. With that said, if you keep blowing thermal fuses, you most likely have an unusual amount of current going through the resistor pack (addition draw due to bad blower, bad wiring or some other issue) and you should address the root problem, and not keep replacing these fuses.
Also do this at your own risk, I am not responsible if anything goes wrong, this is informational only.
1. First step is to take out the glove box. Very easy, pop out the 3 felt covers, and remove the 3 lower screw. Then remove the 3 upper screws, and unplug the 2 wires going to the glove box light.
The glove box should slide out at this point, revelaing the resistor pack.
2. Go to radio shack and buy a new thermal fuse that is the same opperating temp as the blown one (or as close as you can find). I believe the one on there says 216*C, the closest my radio shack had was 229*C I believe.
3. Cut out the old thermal fuse, and warm up your soldering iron.
4. Solder in the new thermal fuse.
5. reinstall the resistor pack and then test the blower to make sure it works on all speeds.
6. Put the glove box back in, and enjoy your cheap fix.
Technically, you could replace this thermal fuse with a straight piece of wire, but you better carry a fire extinguisher with you if you do that. I would NOT recommend doing that!! Unless of course you enjoy melted blower boxes, and dash fires. These resistors can get VERY hot. In excess of 500*F.
Modified by vwgtipowr at 12:29 PM 6-16-2006