OK, this has fixed my dead "high" speed setting that I've lived with for the past 2 years on my 1998 Astro.
Installation was surprisingly EZ. Just remove the 2 grommets holding the washer and cooling fluid tanks (that appear to be melded together). Then disconnect just one hose from the cooling tank to make access even easier (leave the other hoses on if you can). The resistor is down about 10 inches from the top of the tanks and you can easily see the electrical connections going into it. 2 small bolts are all that hold it in. Apparently my resistor had already been replaced by a previous owner because it fit perfectly. The whole replacement took only about 20 minutes. Now I cross my fingers and hope it keeps on working!