I own a 2007 DTS. Battery has drained to dead 2 times in 6 months. Roadside service has replaced battery both times.
I parked the car in garage and came out next day to find no power.
Can anyone recommend a solution or a path to a diagnosis ?
I called local dealer and they indicated no TSB's for that problem.
thanks for helping !

 

it sounds like a fuse/relay blew, you should have2 fuse/relay box in the car and under the hood, there should be reserve fuses and a fuse puller, check all of them, the 10,15,20's , there should be a silver loop in the fuse, if the fuse loops is burnt or broken, then thats the problem, the battery is being drained by this fuse that is blown. i had the same thing..... battery died overnight, and the battery volts reading on the dash would go up and down fast, not stay at say (12v ok), (14v ok)then 5 seconds later (11.3v ok).so i checked the fuses, and it was a 10amp blown, i just replaced it with a reserve in thefuse box.hope this helps. also, it could be a bad alternator, or bad positive wire to the battery, where it moves and it gives no power and move the wire an inch more and it gives power. but i think its a fuse.