Overdrive not engaging
 

My 2001 ranger won’t engage overdrive. I get to 45-50 mph and it starts flashing Overdrive off. I changed out the transmission for another issue, and it had the same problem before. So, I think it’s at least not in the transmission. I think it’s an electrical issue. I don’t really know though.

There have been times where I can even get it up to 65 and it won’t start flashing overdrive off, but I have to sort of step on the gas and hold it there until it shifts. It’s not shifting hard when I do, but it seems like the engine revs higher than normal before it shifts.

I don’t know what overdrive really is. It was explained to me like it’s basically just another gear. Is there an electrical component that engages it, and if so where? Any help is much appreciated.

There's a button at the end of the gear selector lever. Are you pressing it?
Press it once and the "OD OFF" light comes on. Press it again and the light goes out.
The wiring to that button is known to fail / break with time.

I can switch that and it still works like it should, but the higher gears don’t engage except for when I hit the gas and wait for it to shift. Then when I downshift the light comes back on.

" Is there an electrical component that engages it, and if so where? Any help is much appreciated."
In 2001 Ford added an Output Shaft Speed Sensor. I don't know any failure rates or symptoms thereof.
Did you do the trannie change-out you mentioned? I ask because a sensor can be transferred from the old unit to the new.

Flashing OD light indicates a problem with wiring or solenoid.Both solenoids share one 12volt wire, this wire will have 12volts when key is turned on, the 12volts passes thru each solenoid and to the computer, each solenoid has it's own wire to computer, this is the 3 wire connector you see on the side of the transmission. Since a solenoid is just a coil of wire the computer will "see" 12 volts on each wire when key is on, indicating that the solenoid wiring is OK. Flashing OD light means general transmission problem, not necessarily an OD problem, it acts as a warning light, like Check Engine light(CEL), but for transmission.