I have a 97 ford f150 two wheel drive with 224000 mi. Runs Great. Recently the truck has started going in and out of overdrive on its own. I’ll be driving then out of the blue the overdrive off light starts flashing. What’s up with that??
The flashing overdrive light indicates that some fault has been detected with the transmission. When flashing, it is not specific to the overdrive. You need to have the transmission checked ASAP, as more damage is being done to it as you drive. Take it to a dealer or to an independent. Do not go to a chain shop.
Is the light just flashing or is it actually going in and out of overdrive? Do you feel the transmission shift when the light flashes?
In any case, you need to take it in to have a professional look at it. If it is a flashing light, tardis’ advice will help. If it is actually shifting in and out of overdrive, it might be something as simple as a defective overdrive switch, and you can just turn off the overdrive and drive it straight to the shop.