I have a blinking light on my dahboard that says O/D off?

My ford explorer p/u won't drive on regular D gear. R, D1 it does, but very slow. A blinking light on the dashboard says the "O/D is off" What does it mean?

It's probably the way your vehicle is set up to warn you the transmission has an electrical problem. Go to the dealer and have them scan for transmission codes. Your vehicle is in fail safe mode and only has 3rd and reverse gears at this time. You are in 3rd gear when moving off from a dead stop so it's going to feel like no power and slow. Don't go to a transmission garage. They will just sell you a rebuilt tranny.

O/D means overdrive is disabled. That means 4th gear will not engage.