72 dart custom, No turn signals or rear lights?

Brake light switch needs to be connected & probably readjusted.

Turn, running, brake, lights and four way flashers all run through turn signal switch located in steering wheel. Often this switch becomes sloppy from old age & use, and causes problems with above listed lights. One can sometimes test for bad connections in it by gently pull turn signal switch back in direction of steering wheel, and observing if any of the lights begin to work.

The aftermarket radio removal probably disturbed some bad workmanship from when it was hacked in… Ooops, did I say hacked? I mean installed. You will have to probe around under the dash and locate all the bad splices, poor tape jobs, and fix the mess.