code reader not picking up computor system

[COBRA-13]

awhile back i was able to get a code reader on my obd11 connector but now i can't get anything not even any power to the reader. when you first connect it's supposed to flash "pocket scan" (and it works cause i use it on other vehicles) but on my 1998 GMC sierra i get nothing but a blank screen. my truck runs fine and everything seems to work. does anyone know what the deal is or why or what to look for.

 

[bornchevy]

I would check all the fuses in the truck. Most of the GM vehicles that I have worked on have the power for the OBD2 port tied in with the cigarette lighter/power port. Let me know if you find the fuse.