Left Turn Signal Socket Corroded
This is more for information than a question.
I just finished replacing the turn signal socket on my 2009 Cobalt. There isn't any information anywhere on how to do it so I did a little bit of trial and error.
Some back story, the right turn signal stopped working. I replaced the bulbs and it still didn't work. After I started looking at it, I noticed the terminals were corroded and had broken off inside the socket. It's a simple wire assembly and I really didn't want to cut and splice wires so I wanted to replace the wire harness for the entire headlight assembly. Apparently that is extremely difficult. The local parts shop didn't stock it so I headed to the dealer. They wouldn't sell me just the harness and said I could buy the entire headlight assembly, but not just the wiring harness.
So I went back to the parts store and the clerk had a good idea, just find the GM equivalent that accepted the same type of bulb. Only problem is the GM replacement socket has 3 wires and the Cobalt has 5. I decided to take a chance since there were 2 black, 2 brown, and 1 blue wire on the stock assembly. When I got home I noticed on the back of both sockets there were 3 letters; A, B, and G. So I decided to guess. I figured one was a ground, one was turn, and one was for the parking lights. Luckily my guesses worked. I spliced both black together and both brown together so now I had 3 wires instead of 5 that would connect with the replacement socket.
So if you are like me and trying to figure out what wires go to what,
Blue is Turn, Blue connects into A
Brown is Parking, Brown connects to B
Black is Ground, Black connects to G
Only downsize was the new socket didn't quite match up with the old hole in the headlight assembly. The bulb fit but the socket had 3 tabs that were slightly bigger than stock. I used a dremel on the headlamp assembly to cut a small portion of the hole and the new socket fit like a glove.
Hope this helps others.