Turn your flashers on to check the bulbs .Checks good go to your brake light switch mounted on upper part of the brake pedal with a simple test light you should have hot (test light on) when the brake pedal is depressed if not and the ong wire is hot (15 amp fuse in the fuse panel under dash) says STOP by it you need to replace the brake light switch. Also when you replace the battery get the highest cranking amp one that Will fit.