Could be worth temporarily rigging
a large digital voltmeter where it can be watched. If anything in the regulation goes nuts, an alternator
can burn itself out in 30 seconds. If it only goes a little crazy, 16 or 17 volts on the system can eat a lot of electronics and lighting
Very much worth some immediate & thorough testing, and if it is something as easy to fix as a corroded or loose wire...MUCH cheaper to fix the wire.
We diddle the clocks an hour this weekend: Consider it well spent on your alternator.(G)