Alternator problem on 2021 GMC Terrain

[340Cuda]

I am no GM tech but my street car always shows high 13 or even low 14 volt readings even with seat heaters on. You voltage reading seem way too low for a working alternator.

Kind of a long shot but have you had the battery checked?

Maybe a wiring harness problem passed were they were checking the alternator?

Hope you figure it out!