Thank you, JSamp! Very much appreciated. I haven't experienced the wild temp swings yet, and I didn't notice any of the climate control issues, re: hot v cold, but I'm betting you're right about the sensor. If it's corrosion prone, we live in San Diego, close enough to the coast to get sea air. If something can rust, it probably will. I've bookmarked the thread and I'll try to report back what I find just to provide closure on the issue.