Changed battery and the alternator. Evertime i push in my breaks my doors will lock? Guessing my car has an aftermarket alarm system but mainly my problem is i will be driving and i will turn on headlights and the car dash lights will flicker and the rpms will bounce and come right back. Like i said i changed the battery and alternator and the car pulls fine no issues running at all. Just power related. Anyone have any idea things i could check? Also have a sub hooked up. Previous owner installed and its built into where the spare tire goes. Thanks for reading.