Alternator-Battery-Voltage Regulator

[n7163y]

Had Alternator warning light illuminate, voltmer showing 11-12 volts, suspect alternator, removed took to shop, yes its bad.
Replace with rebuilt alternator, flew 11.6 hours just fine, then alternator light comes on, voltage drops to 12 volts or less,
Recharged battery, looks good battery 13.6-14 volts, once airborne drops to 12 volts or less?
Where should I start?

[Eric Jessen]

I was told by an IA that some of the aftermarket alternator kits have crappy mounts and tend to destroy themselves physically due to vibrations etc... You might want to start there.