1999 Ford Explorer flashing 4 wd high 4 wd low indicator lig

Indicator lights flash 6 times both 4wd high and 4 wd low on starting. Keeps flashing on a rhythmical pattern as long as the car is running. No strange noises or smells.
Took the car to a Ford dealer and after 4 hours of diagnostic and testing; they determined that they were clueless as to the problem and solution. The mechanic wanted to change the shift motor on the transfer case as a possible fix. I declined his offer and changed the shift motor myself. But I did have to pay them the shop rate time before I could my keys back and leave.
It will shift into 4 high by the selector switch and back into auto; things work fine mechanically. So it was foolish for me to change the shift motor in hind sight.
I am looking to solve this annoying blinking light situation not an abyss to throw money needlessly.
Solve this problem; then a donation will be fothcoming in lieu of a trip to another Ford Dealership.
Thanking you in advance,
John