Peter,
Thanks for your help. I replaced the blower fuse and ACC fuse and checked them with an ohmeter to make sure they were fine. I apologize for being dense, but explain how you wanted me to check for a switched ground. Also I unmounted the switching unit from the blower cover, and I see the yellow wire, but there's no contact point to test - it's encased. Should I unbolt the black wire block from the switching unit to see the back side? Thanks so much for your help. Mark