2002 Saturn L300 P0621 Fault: Alternator 'L' Terminal Circuit Issue

Hello everyone, I recently encountered a P0621 diagnostic code on my 2002 Saturn L300 with the 3.0L V6 engine. This issue first appeared after several intermittent problems that resolved on their own, but today the vehicle stalled unexpectedly at 35 MPH. I attempted to restart multiple times without success—after sitting for a minute, it started again and ran smoothly all the way home. Notably, no check engine light illuminated during this incident, though I ran the OBD2 scan and confirmed the P0621 code. The P0621 code indicates an issue with the alternator 'L' terminal circuit. While I suspect a short in the wiring or connection, I'm unsure why no warning light appeared—typically such faults trigger dashboard indicators. Given that this is a relatively rare fault for the 2002 Saturn L300, I'm seeking advice from experienced users and experts on how to diagnose and resolve this issue. Any insights into possible causes or troubleshooting steps would be greatly appreciated. Thanks, R