How to Replace a Backup Light on a 4th Gen (2003-09) Toyota 4Runner
Seeing Where You Are Going is Important
Despite accounting for less then one percent of our driving, a large portion of fender benders occur when our vehicle is in reverse. The main cause: failure to see/know what is behind the vehicle. The advent of backup cameras has helped immensely, but for those without one, the backup lights are crucial for seeing behind the vehicle when reversing at night.
Most vehicle backup lights are woefully inadequate; especially the older incandescent bulbs. With a large vehicle that sits high like a Toyota 4Runner, backup lights need to illuminate a large area to get a full picture of what is behind you. When even one backup light burns out, an already dim view becomes even worse.
Replacing burned out bulbs on vehicles are real moneymakers for mechanics and garages. It is simple and easy work that they can charge you a king's ransom for. There is no reason to pay to have any of your vehicles lights replaced; they are easy to do yourself if you have some basic information. If one or both of your 4Runner's backup lights fail, here is an easy way to replace them.
Decide if You Want to Upgrade
Incandescent bulbs do a insufficient job of illuminating. It is in your best interest to have the brightest area possible behind you when reversing. For very little money, you can replace your 4Runner's incandescent bulbs with modern LED lights that will ensure you can see behind you when put select R on the gearshift. Even if your backup lights are still working, I highly recommend replacing them with LEDs. The difference is amazing.
Gather Your Materials
This is the easy part. All you need is a flathead screwdriver and the replacement bulbs.
Access the Old Bulbs
Open the rear hatch of the 4Runner. Near the very back, on the plastic area above the wheel well, is an access panel. They are in the same place on each side. If you are having issues locating the access panel, the one on the driver's side is right behind the access panel for the vehicle jack. There are no pull tabs on the panels, you will need to pry them open with a flathead screwdriver. They come off fairly easy. Once the access panel is removed, you will see a bunch of wires running to a socket, that is the brake lights and turn signals. Directly below that is a brown socket with no wires. That is the socket the backup lights are in.
Remove the Old Bulbs
Get a firm grip on the protruding tabs of the small brown socket and twist counter-clockwise. It will only rotate about 15 degrees, but you will hear a definite “click” when it has been disengaged. Pull the socket directly out and you will have the socket with the bulb in it in your hand. It is tight in that access area, be prepared for some hand contortions.

Inside the access area. The brown backup light socket is directly below the large white socket. There is a bolt between the two sockets.
Tom Lohr
Install New Bulb
Once the socket with the old bulb is out, simply pull the old bulb out. Then, plug the new bulb in. Push the socket back into the hole you removed it from and twist clockwise. You will hear a “click” that will tell you the socket is firmly seated. Replace the access panel by pushing it in.
Enjoy the View
You will immediately notice the difference if you installed LED bulbs. If not, have someone observe while you put the vehicle in reverse to ensure both lights are functioning correctly. This is one of the simplest vehicle DIY projects you can do, don't give your hard-earned money to a mechanic to do it for you. And if you chose the LED bulbs, the difference will be....”illuminating.”