OBD connector not working

[DaNgErOus1998RaNgErOuS]

so my check engine light is on and I went out with my code reader and it is saying that my vehichle needs to be started in order for it to scan the codes, even when the vehichle is on. I know that the code reader is not bad because it works in all of my other vehichles. I think the fuse is blown, does anyone know what fuse it is that runs this? or does anybody know what else might cause this problem??

 

[jasongind]

It will tell you in your owners manual which fuse it is. IF you dont have it let me know and I will look it up for you.

 

[Earl43P]

2000 is #17, 25A Cig lighter / OBDII DLC, in the cab, not under the hood.

 

[explorersportster]

not trying to steal your thread, but i have a similar problem...mine scans with key on engine off, but when I try to run it and scan it says unable to communicate with the vehicle??