When I bought my GN the radio clock stayed on even after key was removed from ignition. After 2 days, my battery was drained. I found a link (from another member) for a repair, I put it in below. I just did the repair last night and it worked, I had a hard time finding an electronic shop that stocked this transistor but finally did. The repair is a little tricky if you have not done electronic soldering and removal. I recommend a good soldering iron and solder removal tool. Contact me with any questions.
Battery Drain
Battery Drain