I have a 2002 Civic EX and the charging system light came on. I dropped in a new battery as the original was getting tired anyway. The car started but charging system light was still lit. I had the alternator tested and it is showing zero volts. I have seen alternators show low voltage, but never zero. Is there a fusible link or something that I should be looking at? I checked the 10 amp alternator fuse in the dash below the steering column and it was good.

Check all under-dash and under-hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post252145

Pay particular attention to:

. Power distribution fuse (80A). It may be under-hood Fuse No. 41.
. ACG (ALT) (S) fuse (15A). It may be under-dash Fuse No. 24.

I suspect the brushes are worn, rotor slip rings need cleaning, or the voltage regulator may be bad. You need to replace or rebuild the alternator. Here's how to replace the alternator:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-2.html#post224856

If you are adventuresome, here's how one common Civic alternator can be rebuilt:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-6.html#post666293

I enjoy rebuilding alternators--it's cheaper and more satisfying. Every do-it-yourselfer should do it at least once.

My gut is that the brushes ($3.50) are so worn that the alternator can't charge the battery. I've seen this on alternators and generators. Replacing the brushes is frequently all that's needed. Afterwards, the Charging System Light goes out and everything works fine.