Battery Light

[yj4x4]

So the battery light came on today.
Plugged in my scangauge and was reading 11.9 ish volts while running. Is it safe to say the alternator is bad?
71k on it, so I'm assuming alternator/battery/etc. is all original.

[Vas]

Look at the battery inside the trunk and see what the date stamped on it is. If it is really old, I would replace it either way.

Also I would disconnect the battery and remove the voltage regulator from the back of the alternator. Inspect it and see the condition of the brushes. If they are really worn out, replace the voltage regulator.

[yj4x4]

From my limited knowledge, the brushes look fine.
Not sure how to read these batteries.
Alternator spins very smooth.

2034020341

[Vas]

Is one brush shorter then the other ?

That battery is original btw and looks to be not fully charged. If you have a volt meter measure the battery with the car off.

Production date of your car ?

[yj4x4]

Put a new (reman) alternator in. Light is off, voltage at 13.9 when running now.
Going to put a trickle charger on it and start shopping around for a battery.
Production date of 12/05.

However now, the airbag light is on...