Be sure to test your brake lights and blinkers with your running lights on and off. You should have problems if that ground in pic 1 above is not connected.
The loose wire should be connected to the side of the bulb socket, which is the ground part of of the socket/plug. I've fixed this on a few 80s by soldering them back on with a decently hot iron, after cleaning wire/housing a bit.
On my 80 the rear wiper started acting up after the wires that...