Check Engine Light

[77broncosport]

I have been trying to figure out why my service engine light is on in my 99 Sable so I can work towards selling it. I have taken it to Autozone to see if they could pull the code that is setting the light, and the reader doesnt power up. I have got some information that said to check that there is about 12 volts between pins 4 and 16 and there wasnt. I found a blown fuse labled diagnos in the inside fuse box, and replaced it and then had voltage between those two pins, but the autozone reader still remains blank. Anyone have any suggestions as to what to check next? I really don't want to have to pay ford to tell me whats wrong is I don't have to.

Thanks
Matthew

[KimMG]

Fuses usually blow for a reason. Did yours blow again? Using a wiring diagram, trace the circuit to find any shorts. If you have a library card, you may be able access your local public library's automotive database from home to get a wiring diagram if you don't have one.