About the same time the center console cigarette lighter quit working which turned out to be a bad ground (the hot lead was OK). I jumpered the lighter ground directly and the lighter and cruise control started working again, so at least one common ground point had gone open.  I have not had time to investigate further and I did not notice anything else not working at that time. 

I have considered running a separate ground wire and tie several of the existing grounds to it, because I have had multiple ground problems over the years. Wonder if anyone else has tried this?

Hope this helps.

Fred