I have a 2008 Cobalt LS. I was just recently notified by a police officer that my driver side brake light did not work however when the brake pedal is pressed the third and right brake light brightens up perfectly. All light bulbs are on and working when I toggle on the lights for night drive. I also checked to make sure all turn signals work by turning on the hazards and all but the back left one doesn't. All lights assumingly work but the turn signal light in the left rear has no activity whatsoever in my findings...the only bulb. Just to verify I tested the turn signals individually and the right blinks at the standard pace while the left one does it at a rapid succession, also shows on my dashboard. Is it just the signal lightbulb that needs replacing? And will that effect the brake light if there is a bad turn signal bulb?