Use a old ice-pick style test light. Start the car, clip the alligator clip to pos + battery and punch/prick the test light into the brown wire at the alt plug. That will bypass all the wiring going to the dashboard. If it don't charge then alt may be bad and if charges check the wires going to dash. Also make sure the red hot terminal has voltage the goes to the starter. It's been awhile but I think there's a fusible link near the starter.
