Hi Dylan,

Try this: Turn the key on to key position II. Observe the warning lights. Battery light in particular. Is it on?

If so, disconnect the small red from the spade lug on the alternator. Did it go out?

If so, put it back on, start the motor, and test the voltage at the small red and the large red. The voltages should be the same but probably are not. Alternator suspect.

But if the battery light is not on in lamp test mode, the fault is an open circuit on the small red, a missing blue ground wire at the alternator, or in the alternator/brush pack/regulator.

Or if the lamp test works, but the light does not go out when you disconnect the small red, there's a short to ground in the small red - usually just south of where it connects to the alternator.
--
Art Benstein near Baltimore

Every calendar's days are numbered.