Just got my M20K out of annual 3 weeks ago (out of state, can't go back to their shop). The alternator (ALX-9525B) and drive coupling assembly were replaced. On Sunday afternoon on a flight home, voltage drops from 13.6 to 12V.
Reset the breakers and the master inflight to no avail. An experienced, local A&P tells me the alternator is bad. It is under warranty but Hartzell wants the alternator pulled and shipped back to them before they will replace it. Has anyone else had an rebuilt alternator fail in less than 20 flight hours?