my 95 has about 300k on it now & occaisionally, will do the same thing. I simply ignore it, as I have a manual switch for lock & od, but if I had to guess as to the actual culpret, I would start at the BCM conector (Body Control Module) & then move over to the conections in the relay box. The Ign. switch is the next thing that comes to mind.
let us know what you find.....