A trailer is normally used to haul a variety of heavy objects that won't fit in (or on) a vehicle. Many trailers, especially large ones, come equipped with rear brake lights. The trailer lights on your vehicle are normally connected to an extension plug on the backside of your vehicle. When you are hauling a trailer behind you, it is required in most states that your trailer lights be functioning normally. If your lights are not working, there are several common issues you can check for.
Check the auxiliary brake light fuse in your vehicle's fuse panel. Open the fuse panel and pull the fuse for the auxiliary brake light with the fuse puller supplied in your vehicle's fuse panel. Check the metal strip inside the fuse panel. If it is broken or burned, replace this fuse with a new fuse of the same amperage.
Check the electrical connector that connects to the trailer. Verify that this connection is secure. Sometimes, the plug ends become contaminated with dirt or other debris. Make sure the connection is solid.
Check the trailer's brake light bulbs. Occasionally, the light bulbs on your trailer will burn out. Remove the electrical connector running to the brake light ballast on the trailer and turn the bulb counterclockwise to remove it. Check the filament. If it is broken or burned, replace the bulb with a new one of the same wattage.
