I am working on my son's 2004 crossfire. He told me a couple weeks ago that his front left turn signal went out. Then about a week later his right front signal went out. Then his left headlight went out. Now his left brake light went out. One at a time.

I have checked the hazard lights, the back two work, front two don't. Swapped the front two signal bulbs but they still don't work. All of the fuses are intact and the correct amperage.

Any thoughts on how to trouble shoot this further would be greatly appreciated. Thank you!