Thanks Bill and Fred. My curtain is controlled by a multiplex switch. If I understand this system, some of the multiplex switches control things like the lights through the PCM, while others directly operate relays for electrical items that have regular fuses in the 12 fuse distribution panel. Am I correct here?
In any event, I have checked every fuse I can find, and my fans are all working, so I must have other problems. There is no voltage at the wires that the curtain plugs in to.