Generation III External Engine - Sudden drop in voltage from 14 to 11

All of a sudden my check gauges appeared and the alt. voltage is at 11. I had the alternator rebuilt about 500 miles ago to put out more amps. It's been running about 14.5 The odd thing is the voltmeter reads 12.1 at the battery and driver side battery pole with the car off. My harris speed works and dashboard is reading low. Oddly the car drove all the way home but seems to lack voltage because the lights won't come all the way up on one side. Can alternators just change their charging ability from 14 to 11?

its called......the alt took a dump on me

I 2nd sjsingle, alternator took a dump on ya. The Alt in my Nova went out last summer and I had al lthe same symptoms. Still ran for a day or 2 even! Better go get your money back, and just buy a 130AMP alternator!

i have to be the third to agree sounds like the alt. you can check power coming out of alt to be sure

The alt only making ~11VDC while running usually points to a single failed diode in the rectifier. With 2 working diodes the alt can still make about that much voltage under load.

Some shops use cheap Chinese rectifier assemblies with 45amp diodes instead of the factory 55amp spec, they run for a while and then pop. Depending on what your shop modified to make it output more power, it could be that the diodes aren't up to the load.

I'd pull it off the car and take it back to the shop for teardown.