I have '98 rango, 95K miles, rund like a champ, pulling boat, crossing mounting in Md, OD OFF Lite came on, stayed on till I crossed mountain and going down other side. I was babying the thing at the time, not lugging nor flogging the motor. I am guessing the lite indicated a hot tranny that would not go into OD if requested. Anyone ever see this ??/

 

You are correct in your assumption. When transmission temp reaches approx 260 degrees F, OD operation is inhibited and the OD off light comes on. When it cools to approx 230 degrees F, OD operation is allowed.