dat LS2 rx7

Ok so I'll explain my wiring issue as best I can. Started off one day my radio seemed to just randomly keep shutting off and starting back up. Later I traced the cause to be whenever I'd press the brak pedal. Once it got dark out I realized that pressing the brakes also causes all my lights to dim down as well as my temp gauge to read that it's overheating. Then I found out that my headlights also contributed to making the gauge move up higher. But one thing I noticed is that the problem is a lot less bad when I'm not moving. I've looked around for a problem similar to this with no luck. Cars a 92 S13 with a blacktop SR if that matters. Any help is greatly appreciated. I'll post a video in a sec