Here's a simplified wiring diagram of the alternator circuit for the 1992 2.3L Ford Ranger. The 1993-1994 alternator circuit wiring diagram is in the next page.
Testing the alternator, to see if it's charging or not is a pretty simple test, especially of you have a wiring diagram! Hope it helps.
One thing to note, is that the 12 gauge inline fusible link (that protects the alternator's battery circuit connects to the starter motor relay. This starter motor relay is bolted to the firewall, next to the battery.