96 F150 can't read computer

I have a 96 F 150 with 5.0 auto. Check engine light is on but scanner won't communicate with diagnostic system. I have tried three different scanners with no luck. Including newest Snap-On version.
Anyone have experience with this in past?
Thank You for any and all help.

Have you checked all the fuses under the dash? If the fuse to DLC blows light will come on and no communication.

Thanks, I'll take a look.

Are you using a OBD2 code reader?

Using OBD2 scanner with Auterra software.