2000 SEL Check Engine but no codes

CEL just came on - 2000 SEL w/ 91,000kms on it.
I've had it since new and it's had no prior problems and it still runs great, so I took it to AutoZone, but their reader would not link up to the OBD port. They tried it on another Ford and it worked no problem. Tried it 3 or 4 times on mine, but it wouldn't even link up or display anything.

Any thoughts?

TIA.

It may be a fuse. I am not sure of which one but I think someone had the problem when the lighter fuse blew. I also seem to remember fuse #17. I don't know for sure nor do I know the years of the ones I am talking about but do check your fuses as at least one of them powers the OBDII port.

Thanks! Fuse#17 was blown (not sure why).
I guess I can get the codes read now.