This is what the back of my car looks like at night when I turn my headlights on:



The brake light works fine and lights up perfectly when I press the brake. However, just driving around with my lights on it won't stay lit like the passenger side, and the side light is extremely dim.

Checked everything out. Wires seem fine and the bulb for the brake light was replaced. Any ideas? Thanks.

 

Left tail light bulb would be my first guess.

 

I'm trying to figure out mine, as well. But it's just the high-mount (third) brake light. Fuses are good and changed the 7440 brake light bulb.

 

Check the wiring. Mine had the same issue and I found that the wiring was messed up. Look at the little rubber piece on the left side of the trunk and see if the wire is exposed and frayed.