OBS Battery Light Low Voltage

[TexasAggie09]

Howdy y'all, typing on my phone so forgive me for being short. On a 5 hour road trip, looked at gauge cluster right before boarding ferry and saw battery light on. Voltage while running according to gauge is usually 14 while charging. Now of reads ~10. Have no access to volt meter, both batteries 850 cca motorcraft, truck idles fine and starts fine but always low voltage. Don't know if running down batteries or bad reading. As far as I know, stock alternator with 224k miles.

No access to alternator shop, only autozone and oreilly. Only have tomorrow morning to fix it.

What do y'all think? I'm thinking alternator is dying.

[turbocharged]

I would agree with you under these circumstances. I just really hate replacing parts without troubleshooting, but you say no access to a volt meter, so I would have to agree with replacing the alternator. I would just hate for you to replace the alternator and still have the same issue.

If you have time, and your planning on replacing it anyways, you should uninstall it, and take it apart, I would clean the contact side of the rotor, and lightly file down the brushes and then put it back together and reinstall to test it.

I have managed to save a few alternators using that little trick, and if it doesn't work, then hey, you were gonna replace it anyways.