1968 dart no brakelight left side but have on right..

Just to help- there is one brake light wire going into the switch and that is where it splits into left and right. When you make a turn, the switch must cancel the brake light for that side and allow that side now to flash as a turn signal. Don't be afraid to remove the wires from the connector. To re-install, just match the wires from the other side of the connector.