Whats wrong:2000 Ford Ranger takes a long time to shift to 2nd gear. Also the overdrive light is flashing?

The overdrive light flashing, is just like the check engine light coming on when the computer sees a problem in the electronics for the engine system. The flashing overdrive light indicates that something is wrong within the transmission, maybe just electrical, like a sensor, or a mechanical malfunction. You will need to take it to a garage or dealer for determination as to what is going on.