Okay so I have some issues in my 1970 mustang and I don't know where to start looking. Basically the turn signals only sometimes work the dash lights are pretty dim, and one of the headlights turns on only when it feels like it. Also the radio sometimes turns on but most of the time the speakers don't work. Occasionally I'll be driving and the head unit will randomly turn on and work and then shut off ten minutes later. The radio and speakers are aftermarket. What should I start looking at? Are the issues likely related?