The flashing OD light is the tranny's way of telling you something is wrong with it.
A code is being generated that can be obtained with a scan.
If you can, drive it to a Midas, Monroe, or any close-by place that will do a scan for around $20-$30.
Steve - TCCoA member
2003 Crown Vic LX Sport
1995 T-Bird LX 4.6 retired at 247,888 miles
Thanks for the ride !