Don't drive my DTS in the winter so I guess the parasitic drain took the battery down. Charged the battery and took it out for a couple of drives . All was fine except the sunroof was dead.
This was a little scarey as I couldn't imagine the cost to replace a motor or the unit itself. Went on line found a similar problem with a Jeep. The guy simply disconnected the battery terminals and it worked. This also worked for me. Great piece of advise in case you are one of the thousand's of owners of "Factory" installed DTS sunroofs that were not factory installed at all!
This is the GM "factory" sunroof that was installed after the vehicle left the assembly plant.
Many DTS had "Factory" sunroofs installed at shipping Depots before they were shipped to the dealer. (DHAM assembly plant had a 3 vehicle spur line off the main line that could only process 9 sunroof vehicles per hour
All is well with mine now!