CheckMotor in Ford Explorer

I have a Ford Explorer 4 x 4 year 1991, I do not know how to find the port of Escanner Paray at the same time where to find repair codes ...

The light of Check Motor is preserved on and the alternator does not send load to the battery and presents a defect as if it were a spark plug but it is not ... that's why I need the repair codes and how to find them?

I recommend you before doing anything, that you repair the alternator if you do not load your battery, it is most likely that it without coals, solve this you first want the lack of current it produces failures when walking, and that that works loose can pass through the regulatory box that symptom that symptom is very similar and in those conditions the battery does not charge.