You're describing a rather common problem on all car brands. Follow the smaller positive battery wire to the under-hood fuse box, (power distribution center), and tighten those nuts. If they're tight already, remove that connection and clean the surfaces.
If you have to remove that connection, standard procedure is to disconnect the battery's negative cable first, then it's safe to work on any part of the electrical system. If you don't do that first, you can cause a huge spark if the metal tools you're using on the PDC touches that connection and anything metal on the car at the same time. Most people are aware of this. With this simple caution, tightening that nut just takes a few seconds.
You may find more useful information in this article:
https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked
Let me know if that solves the problem.
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Sunday, February 12th, 2023 AT 3:26 PM