99 blazer 4x4 200k miles the check engine light is on running bad, plugged scanner in but would not start, it seems i have no info to scanner, help, what am i looking for? scanner is not starting.

 

Sounds like a bad scanner or your plug in the truck is bad. Even if there's no codes to be read (which it sounds like there are) the scanner will still pull up info about the vehicle.

 

I am not sure if it applies to your vehicle but I remember something about the cigarette lighter fuse. If its blown the OBD port will not work.

 

Yep, check the lighter fuse. It also powers the OBD port.

 

See now I learned something that I never knew!! Thanks guys