Just noticed that my left brake light isn't working. Checked the bulb and it looks fine. swapped the right and left bulbs and they both work on the right side, but not the left. It didn't make sense that it would be the fuse, but I went ahead and changed this, but still the left brake light doesnt' work. Any ideas what to try next?

You probably have a damaged wire or bulb contact inside the left socket. You will need to check for continuity in the wires before the light socket to make sure you actually have power going to the left side.

Get yourself a cheap multimeter that can read DC voltage and start checking for a broken wire or loose connection working from the light socket backwards until you find power.

I am lead to suspect my first comment. Damaged Contact.

a lot of frontiers had that problem due to manufacturer the socket is probobly bad they had done a recall on them