Brake lights not working

Good evening,

The brake light switch sends a signal to the body control module and the module sends power to the lights.

https://www.2carpros.com/articles/how-to-check-wiring

There is a fuse for the switch which I circled in the fuse diagram.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Make sure you have power to both fuses I circled.

Roy

Hello, I'm Danny.

I've attached a wiring diagram of the exterior lights below for your SUV. I've cut the pictures in half so you can view larger. Here is a tutorial on how to test wiring:

https://www.2carpros.com/articles/how-to-check-wiring

Hope this helps and keep us updated as to what you find. Thanks for using 2CarPros.

Hello,

I have seen the brake light switch and the flasher module stop working to cause this issue here is guide and the brake light wiring diagrams so you can see how then system works and which wires to test to see where you are losing power.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.

Hello,

There is a flasher module under the fuse box that goes out.

Here is a wiring diagram and the location of the flasher module so you can take a look and do some testing here is a guide to do so:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check for power at the fuses as well.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check out the diagrams (below).

Please let us know what happens.

Cheers, Ken

Good afternoon,

Did you verify power in and out of the switch for the brake lights?

The orange wire is power from the fuse block and the white is power out to the turn signal switch.

Roy

Hello, there two fuses for the brake circuit, you need to check the fuse circuits, to see if they are hot.

The stop lamp fuse is hot all the time, supplies voltage to the brake switch.

The vehicle stop fuse is after the switch, goes hot when you step on the brake. Both fuses should be in the underhood electrical center. Driver side brake lite voltage, lite blue wire.

The brake light switch was working because the center brake light worked. From that switch, current for the other two lights goes through the turn signal switch, and that is a common suspect. We also have to look for overheated connector terminals, but that is not a good suspect because the amount of current flow in that circuit is not sufficient to cause much trouble, and it has a small chance of affecting both the left and right circuits at the same time.

If the two rear brake lights quit at different times, a good suspect then is someone added a trailer wiring harness years ago, and spliced the wires to the truck's wires with Scotch-Lok connectors. Those do not seal out moisture, so the wires will corrode over time, and lead to dead circuits.

A corroded ground wire for the rear lights is another common suspect, but that will include the tail lights and license lights. Depending on whether one or two ground wires are used, all of the rear lights could be dead, or only all the lights on one side could be dead. The second condition can be misleading because a turn signal light can falsely appear to be working because it gets a ground, (a poor ground), through the interconnected light on the other side. The symptoms will be confusing, and quite different than what you described.

Hello, does the high-mount brake lite work? If none of the brake lites work, check the feed to the brake switch. The switch should be activated by the brake pedal arm. Orange wire is hot all the time, white wire goes hot when the switch is activated.

Your brake light wiring harness may be faulty or wiring harness plug may have come loose. If your cyclops is working then the stop light switch is working.