Testing to Determine Backup Light Wire Location on 2005 Toyota Sienna

Question:

I installed the 7-way connector using your video as guidance. My trailer has backup lights but the instructions dont show where I can tap in to the vehicle wiring to run the trailer backup lights. Id rather not pick it up from the rear hatch because those wires disappear into a bundle up near the hinge.

asked by: Jim B

Expert Reply:

If you want to access your Sienna's reverse light circuit to allow your trailer backup lights to function you will need to either find the wire for the reverse light circuit at the back of the vehicle, either at the harness you mentioned or right at one of the tail light assemblies, or you could find the fuse for the reverse light circuit in your power distribution box and tap into that circuit using a fuse tap # F2526. One way or another you need to get to a wire that carries that signal. I found an online manual that indicates the backup light fuse is number 34 in the interior fuse panel located at the driver-side dash.

It may be easiest to access the reverse light signal at the rear of one of the tail lights. You can usually determine the correct wire by sight, by removing the assembly and noting which wire connects to the reverse bulb. A circuit tester like # PTW2992 allows testing without having to trace the wires all the way to the bulb. Doing this means having an adult helper who can shift the vehicle into reverse with the brake pressed and emergency brake engaged so you can safely test the wires.

Once you find the correct wire you can tap into it with a quick-splice connector such as # SWC501915-1 and route a length of extra wire from the splice to the 7-way center pin.

expert reply by: Adam R