is it possibly when your headlights turn on? there are setting in the new vehicles that I would check first. also make sure there are no papers or anything blocking the little sensor button on the dash for your lights.
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Sounds like a bad dimmer switch. Try moving the switch and see if it acts up. Dont forget to turn on the headlight when doing so. Otherwise you may have a problem with the charging system.
this happens when the lights are on or just parking. only the dash lights go dim