Od Light Blinking

My 2002 ford explorer started to have a blinking OD llight in the dashboard , but nothing seems to be wrong and the vehicle runs OK.

It is telling you there is a problem in the O/D system somewhere. Have the codes read and post back the EXACT code number. Major parts chain stores will read the codes for free. It should be something like a P07xx

Also check the fluid level. First sign of low fluid is usually trouble with the overdrive in a Toyota. Might be the same for many other vehicles.

Actually the OD light blinking is your Transmission "check engine light". Normal scanners like the ones used at Autozone will not pull transmission codes. Go to any Transmission shop and they will pull the codes for you for free in hopes of ripping you off, just dont leave your truck with them.........Make sure you stand there with them and watch the scanner and write the codes down yourself (dont let them take your truck in while you sit in the lobby.....). Post back with the codes and also your engine, milage, 4wd, recent tranny service?....etc.