Brake lights not working

Hi and thanks for using 2CarPros.

The first two pictures indicate where the grounds are located. Both are located below the tail light assembly.

Now, to determine if this is a ground issue is simple. First, note that all of the tail lights ground at the same places. So, chances are, if the others work, the ground is good. However, it doesn't hurt to check and confirm. Simply get a test light and find a known good ground on the body of the vehicle. Check to see if power flows through the test light when the brake is pressed. If it does, then the new ground you made with the light has completed the circuit indicating the one on the vehicle is bad.

If you look at the schematic, disconnect the plug and check the yellow/gray wire on the left light and the yellow/brown wire on the right for power. You will need a helper to apply the brakes so you can see if there is power.

If there is no power, then you need to check the tail light warning center in the trunk (left side) See picture 3.

(Note: In picture 3, I highlighted the wires you need to check.

On the warning center junction, you need to check three wires for power. First, the solid yellow wire is direct from the brake light switch and should have power when you apply the brakes. However, if the third brake light is working, then there has to be power to the yellow wire. If the third brake light isn't working and you have no power to the yellow wire, then nothing is coming from the switch which you replaced. Check it for connection, make sure nothing is damaged, the switch is properly adjusted, and there is power to it.

Next, if you find power to the yellow, check for power out to the yellow/gray and the yellow/brown. Once this is determined, then:

If power and you know the light assemblies have a good ground, there is an broken or damaged wire to the tail lights. If there is no power out, replace the warning center junction.

If you have questions or need help, let me know. Also, let me know what you find.

Take care,
Joe