I need to know where the rear turn signal/brake light relays are located.

Does the left brake light work when brake is applied ? The power to the parking light filament needs verification

If both the brake lights and rear turn signals are not functioning in your 2008 Dodge Charger, there are several possible causes to consider. Here are some common issues that could lead to this problem:
1. Blown fuses: Check the fuse box for any blown fuses related to the brake lights and turn signals. A blown fuse can interrupt the circuit and prevent the lights from working. Refer to your vehicle's manual to locate the specific fuse for these functions and replace it if necessary.
2. Faulty bulbs: Inspect the bulbs in the brake lights and turn signals to see if they are burnt out or damaged. If a bulb is not working, it should be replaced. It's possible that multiple bulbs have failed simultaneously, leading to both the brake lights and turn signals not functioning.
3. Wiring issues: Check the wiring connections and harnesses for any signs of damage, loose connections, or corrosion. Faulty wiring can disrupt the electrical flow and prevent the lights from operating. Repair or replace any damaged wiring as needed.
4. Malfunctioning brake light switch: The brake light switch, located near the brake pedal, activates the brake lights when the pedal is pressed. If the switch is faulty or misaligned, it can cause the brake lights to not work. Consider having the brake light switch inspected and replaced if necessary.
5. Faulty turn signal relay: The turn signal relay controls the flashing of the turn signals. If the relay is defective, it can prevent the rear turn signals from operating. Consider replacing the turn signal relay if other potential causes have been ruled out.
If troubleshooting these common issues does not resolve the problem, it is recommended to consult a professional mechanic or authorized Dodge service center for a more accurate diagnosis and repair. They will have the expertise and necessary tools to pinpoint and fix the specific issue with your 2008 Dodge Charger's brake lights and rear turn signals.

The same relay won't be doing the turn signals and the brake lights. The most obvious thing apart from bulbs is the brake light switch, which is easy to test with a multimeter.

https://www.google.com/search?q=2001+mercury+sable+brake+light+switch

and it is a known issue!

https://www.google.com/search?q=2001+mercury+sable+brake+light+switch+problems

....

First remove and test the brake and turn signal bulbs, if ok energise the brake and turn signal circuits, connect a voltmeter to the center of the bulb holder to shiny part of the metal body frame , should be battery voltage if ok the light frame has a bad earth,if no voltage a bad connection or broken wire going to the light.

Stop Lamps
The brake pedal position sensor is a resistive device used to sense the action of the driver's application of the brake pedal. The brake pedal position sensor provides an analog signal that will increase as the brake pedal is pressed.
The brake pedal position sensor receives both a 5-volt reference voltage and a low reference signal from the electronic brake control module (EBCM). When the brake pedal is pressed, a variable signal is applied from the brake pedal position sensor to the EBCM through the brake sensor signal circuit. The fuse block left rear supplies battery positive voltage to the bass relay switch through the BASS fuse. One side of the bass relay coil is permanently grounded at G402. The EBCM supplies voltage to the bass relay coil upon receiving the signal from the brake pedal position sensor. The switch contacts of the bass relay close and battery positive voltage is applied through the bass relay switch to the center high mounted stop lamp (CHMSL), and to the turn signal/hazard flasher module through the stop lamp switch signal circuit. The ground for the CHMSL is applied from G402. The turn signal/hazard flasher module then supplies voltage to the left and right stop lamps in the tail lamp assemblies that have ground at G401 and G402. For export vehicles the stop lamps receive battery positive voltage directly from the bass relay.

Do you know where the rear fuse box is ? Check BAS fuse 15amp. and the bas relay , should be marked on the inside of the fuse box lid . The rear fuse box is located

Fuse Block - Left Rear
In the passenger compartment, under the left side of the rear seat at carpet
Power and Grounding Component Views
Electrical Center Identification Views
Fuse Block - Right Rear
In the passenger compartment, under the right side of the rear seat at carpet.

If fuse and relay are ok your best would be to take to a cadillac dealer .

The high mount brake light gets its own signal from the brake light switch (on the brake pedal). Or at least the wire leaving the brake light switch will splice, one wire to the high mount brake light, and the other for the rear brake lights is routed through the turn signal switch, and coordinated there with the turn signal wires to the rear brake lights. The brake wires and turn signal wires share the same wire, and same filament in the bulbs. It is kind of complicated, but brakes applied with no turn signal, brake light wire goes from brake light switch through the turn switch and out to the bulbs. If brakes applied with turning signal, non blinking brake light wire goes from turn switch to rear light, while the turning signal wire will go through the flasher relay, and then to the rear light to cause blinking.

I hope that makes sense. It appears the problem may be in the turn signal switch for both the turn signals and the rear brake lights.

The circuit goes from the brake light switch thru the turn signal switch and uses the same bulbs as the rear turn signals. I would check for power in and out of that switch next.

the brake lights and the rear turn signals should be the same bulb check the bulbs to make sure they are not blown does your third brake light work if all brake light are out and the bulbs are good check the brake light switch on the brake pedal

The brake light switch located above the brake pedal may be faulty or needs adjustment.

Hi,

If I understand you right based on your post/description, the signal lights would still turn on even if any or both of the flasher relays are removed. Should this be the case, then the signal lights are not getting the power from the flasher relays but from the brake light circuit.

Perhaps your concern is not with any of the flasher, but simply missing or loose ground more particularly with the rear lights. Perhaps you could try determining which of the wires for the brake lights and signal lights (as they come out of the light assembly) would be ground . A test and even possibly a temporary workaround is to hard wire a second ground connection from the determined ground wire of the lights and attach it to any conveniently located bolt or screw to the body. it may be to your advantage to do this on all the rear lights assembly.

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards. Thank you for using FixYa.