I have a 2006 wagon and just found out the lower brake lights are not working. However, the upper brake light on the "spoiler" is which I assume means the brake light switch is ok.

I checked the STOP fuse. I checked the lower bulbs and both filaments in both lights look to be intact.

Any ideas? If it is a grounding issue, does anyone know where I can check the ground wires? I do not have a maintenance manual.