The voltage is to high.
The voltage regulator needs a seperate small wire from the chassis battery to monitor and control it.
With the voltage regulator being in the alternator, you need a alternator with a regulator sense terminal. It may be there but not hooked up.
On some, there is a 4th smaller terminal on the isolator that works around the alternator sense terminal. That small terminal would need power when the key is on.
Linear Mode
