I have a problem when I put the running lights and or headlights on the left side only turning signal lght come on too, something is making that left side only turning light come on, all so the driver side, side running light has 2 wires that if you put a volt meter on each wire you get a 12 volt plus reading , not groung reading at all, I think the color on the wires is blue, and brown.
Ron

Does the light flash or just come on? A lot of times they come on to let you know that one of you running lights on that side are not working right you might check them all.

Ant

The brown wire is the running light, the blue is the turn signal. Generally, you will find that the ground wire is bad to the light (could be front or rear). The front fails more often. It is most likely to be the black ground with to the socket is broken inside the socket. They are a common replacement part at the parts store, or cut a used one off another car (common to most all GM of that era).