Ford Repair: OVERDRIVE LIGHT, ford explorer 4wd, electrical problem

Question
I HAVE A 2000 FORD EXPLORER 4WD 4.0L V6 EFI.
WHAT WOULD CAUSE THE OVERDRIVE LIGHT TO BLINK WHILE DRIVING THE VEHICLE? THE OVERDRIVE BUTTON IS OFF WHEN IT BLINKS. THE VEHICLE DRIVES FINE AND HAS NO HISTORY OF TRANSMISSION PROBLEMS!  

Answer
There is always a electrical problem with the transmission when the overdrive lite blinks. Have you ever had the transmission flushed, and a new filter installed? I would start there, before anything else. Alot of people will change their oil on time but they let the transmission go.. Thanks