99 Ford Windstar O/D off light blinking?

I had recently replaced the in my 99 Ford Windstar with a brand new transaxle, but whenever it shifts into overdrive the O/D off light starts blinking. I can still cut the overdrive off, but the blinking doesn't stop. There is also no noticeable odd shifting problems. I'm figuring it either the VSS or Range sensor. Any info would be appreciated, Thanks!