So I drove my Chevy Impala this morning and it was perfectly fine, and about 3 hours later, I got back in and tried turning it on, but literally nothing happened, My car has had a check engine light on for a while, and I saw it turn on for like a millisecond but that's it. I got out of the car and the locks wouldn't work either. I hadn't used my car in about a week before today, and I realized I accidentally left my dash cam connected the whole week (it stays on when car is off) so is it just a dead battery?
I might be. Just check your battery voltage for now.
If nothing comes on when you turn key to the on position, check to see if the battery cables are loose at the battery. They can make intermittent contact and drop out voltage. If lights do come on, turn on your headlights and then try to crank the engine. if the lights dim, you need a battery. If they do not, if you dare to tap on the back end of the starter with a wrench or hammer a few times. Be very careful not to come into contact with the battery cable on the solenoid of the starter. If it starts you will need a starter. The brushes in the starter are worn out.
I hope you find this helpful.