Welcome to 2CarPros.
You found the reason the license plate lights don't work. I have to ask you a favor. Can you take a picture of the wires in questions and upload them for me to see exactly what you are dealing with? The brown wire should have power to it when the parking lights or head lights are on. If you could check that for me it would be very helpful. The black wires should be grounds for the lights in question.
It is really easy to test for power. All you need is a $3.00 test light or voltage meter. I am going to provide directions for checking. There are three links I will attach. The first explains how to use a test light, the second relates to a volt meter (or multi-meter), and the third simply shows how to check wiring.
Here they are:
Okay, please don't be worried about the testing. It's hard to do it wrong, and the worst thing that may happen is a fuse may blow.
Now, I attached three pictures for you to look at. These are portions of the wiring schematic for your vehicle. I circled everything that relates to what you are dealing with. As you will see, power is supplied via the brown wire and ground is supplied via the black. Take a look at them.
Next, if you found a broken wire, there should be two sides to it. Is that correct? If it is, chances are you will have to do nothing more than rejoin the wires to the correct colors. Again, worst case is you blow a fuse. There are a couple ways to fix the wiring, but the easiest way is to simply use a butt connector. Take a look at picture 4.
I placed two sad looking arrows toward where the two wires enter. You simply remove a small amount of the insulation from the wire (approximately 1/2"), push the wire into the end of the connector, and crimp it with pliers. Just make sure it is tight and can't come out.
Also, the connectors come in different sizes. The picture I attached shows a yellow one which will be too big inside to work for these wires. Most likely, you will need red or even blue.
If you could upload a pic of what you found, I can help you through it. Please feel free to let me know if you have questions or need help. Also, note that the wiring in the pictures is located on the left side (driver's side) trunk area.
Take care and I'll watch for your response.
Images (Click to enlarge)
Monday, May 27th, 2019 AT 8:32 PM