I identified a problem with my car, which was the relay box.
14V was getting in, passing the relay, and when going out the relay box to the wire, it would pass only 13V.
So, whenever I turned the lights on, 0.5V would be removed, and if the fan kicked in, another 0.5V would be removed. In the end, I would see 11.8V in the logs.
Check wiring for voltage drops.