All of a sudden my brake lights won't light. a week before;my turn signal switch broke.My fuses are good. my brake light switch is working. my tail lights are working also.do a year ago the same thing happened, then they magically started working again. do you think it is a ground problem?

If your 2010 Crown Victoria has functioning headlights, brake lights, and turn signals but no tail lights, the issue could be with the tail light circuit or with a specific component in the tail light assembly.
Here are a few things you can try to troubleshoot the issue:

• Check the tail light fuses. Make sure that the tail light fuses are not blown. Check the vehicle's owner manual for the location of the fuses.
• Check the tail light bulbs. Make sure that the tail light bulbs are working properly, if not replace them.
• Check the wiring. Make sure that the wiring for the tail lights is connected properly and that there are no frayed wires or broken connections.
• Check the brake light switch. The brake light switch is responsible for turning on the brake lights when the brake pedal is depressed. Make sure the brake light switch is working properly.
• Check the turn signal switch. Make sure the turn signal switch is working properly, and properly wired to the tail lights.

If the problem persist after trying the above solutions, It would be best to consult a professional mechanic or an auto electrical technician to diagnose the issue, as it could be a malfunction in one of the electronic module that control the lighting. It's a good idea to take the vehicle to a dealership or repair shop that specializes in Ford vehicles. They will have access to the wiring diagrams and repair information needed to correctly diagnose and repair the issue with the tail lights.

Tail lights typically use the chassis (ground) for the circuit return path. Are all tail lights out or just the brake lights?

If rear brake, turn signal, and backup lights are out then likely a ground has failed.

If rear turn signal and hazard lights work amd only the brakes not working then it's more likely a control device (brake switch, etc.)

Turn signal tail lights and BRAKE LIGHTS NOT WORKING

It can be faulty brake light switch causing the problem or its blown brake light bulb. First check and confirm brake light lamp is working and that's not the case.

For turn signal not working it can be faulty turn signal switch or its issue with wiring:----

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To trouble shoot brake and turn signal related problem, check the help links mentioned below:-----

Click the link:----
1996 Buick Regal Grand Sport Brake light Switch Location? http://schematicsdiagram.blogspot.in/2012/04/1996-buick-regal-gran-sport-brake-light.html

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No brake lights on Buick? http://schematicsdiagram.blogspot.in/2012/04/no-brake-lights-on-buick.html

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Brake lights not working on 1989 BUICK REGAL?

http://schematicsdiagram.blogspot.in/2012/04/brake-lights-not-working-on-1989-buick.html

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How to replace Brake light switch on Chevrolet Tahoe?

http://technoanswers.blogspot.in/2012/02/how-to-replace-brake-light-switch-on.html

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How to replace Parking, turn, and Brake Lights on car?

http://schematicsdiagram.blogspot.com/2011/06/how-to-replace-parking-turn-and-brake.html

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Upper brake lights work, but low brake light not working?

http://schematicsdiagram.blogspot.com/2011/12/upper-brake-lights-workbut-low.html

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1997 Cadillac Catera: How to replace Brake Light Switch?

http://howtobyme.blogspot.in/2012/06/1997-cadillac-catera-how-to-replace.html

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2003 Chevrolet S10 Tail light Fuse http://schematicsdiagram.blogspot.com/2012/11/2003-chevrolet-s10-tail-light-fuse.html

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Chevrolet Parking light and Tail lamp light Wiring diagram http://schematicsdiagram.blogspot.com/2012/11/chevrolet-parking-light-and-tail-lamp.html

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Car Tail Lights Not Working?

http://schematicsdiagram.blogspot.com/2011/12/car-tail-lights-not-working.html

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Turn Signal Not working http://technoanswers.blogspot.com/2012/11/turn-signal-not-working.html

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Right turn signal not working on Pontiac Car?

http://schematicsdiagram.blogspot.com/2011/12/right-turn-signal-not-working-on.html

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Only one side indicator light working on car?

http://schematicsdiagram.blogspot.com/2011/12/only-one-side-indicator-light-working.html

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Turn signals not working on 1987 Jeep Wagoneer? http://schematicsdiagram.blogspot.com/2011/12/turn-signals-not-working-on-1987-jeep.html

1996 Chrysler LHS brake light circuit wiring diagram?

http://technoanswers.blogspot.in/2012/02/1996-chrysler-lhs-brake-light-circuit.html

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How to replace rear Brake lights on 2004 Toyota RAV4? http://schematicsdiagram.blogspot.in/2012/02/how-to-replace-rear-brake-lights-on.html

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One brake light on driver side not working, but other lights work?

http://schematicsdiagram.blogspot.com/2011/12/one-brake-light-on-driver-side-not.html

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2002 Lincoln Town car Fuse Box http://schematicsdiagram.blogspot.com/2012/11/2002-lincoln-town-car-fuse-box.html 2007 KIA Rio: Brake Light Fuse Box Diagram?

http://repairhelpcenter.blogspot.in/2012/06/2007-kia-rio-brake-light-fuse-box.html

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Overhead Brake lights not working on 1999 GMC Sierra 4x4?

http://technoanswers.blogspot.in/2012/03/overhead-brake-lights-not-working-on.html

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2004 Ford Mustang: Brake light Fuse Location?

http://howtobyme.blogspot.in/2012/05/2004-ford-mustang-brake-light-fuse.html

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These will help.

Thanks.

I'm checking into that same problem for a early 90's buick ( it's a GM also ) , I've checked the obvious ( bulbs, flasher,fuses,etc) all where fine. I assume your front turn signals work if you manually operate the turn signal switch or put on the hazard switch? The Buick's rear lights won't come on even with the hazard switch on. When you say one tail light has been out for some time, do you mean the brake/signal light or park/running lights? The Buick was like that with one side out for a while ( brake/signal light) but both the rear park/running lights work. Now, I've narrowed the problem down to the turn signal switch. I'd bet money on it. I just have to dig out my steering wheel puller, bite the bullet and get 'er done. You should be carefull if you're attempting that repair yourself ( AIRBAG ), use a manual. ( You could do a quick test by trying the turn signal while you pull the bottom of the arm toward you,move some of the wiring in the column near the arm,etc. I did and the signals started working. Could be the switch,dirt or a broken/loose wire. there's a lot of wiring going through the column and a lot of movement ( turn signal,high beam,cruise, then add tilt) Hope this helped.

check for power at the wires going intop the tail lights, real common that the circuit board is bad, but unlikely both at the same time. The tag, tail lights and brakes are 2 different systems. Do the turn signals work normally? if so the wiring from the turn signal switch to the brake lights is GOOD. the stop light switch had\s a ORANGE wire that should have 12V if not ck STOP LPS fuse, when brake pedal is depressed, the WHITE wire is 12V (at the stop light switch) if that is OK, the turn signal switch COULD be bad. The wiring harness plug is near the back left under the tailgate, see if that is disconnected?

CHECK TURN SIGNAL FUSE.IT COULD BE BLOWED OR YOU HAVE FAULTY TURN SIGNAL SWITCH.BECAUSE BACK LIGHTS AND TAIL LIGHTS SHARE SAME CIRCUIT WITH TURN SIGNAL SWITCH.

Sounds like a blown fuse or a ground wire broke.

WITH A GOOD FUSE TESTER, TEST ALL THE FUSES FUSEBOX UNDER THE HOOD & INSIDE THE VEHICLE. IF THE FUSES ARE ALL GOOD WITH THE TESTER YOU MUST HAVE A BAD BRAKE LIGHT SWITCH OR A BAD TURN SIGNAL SWITCH. THE BRAKE LIGHT CIRCUIT GOES UP THROUGH THE TURN SIGNAL SWITCH & THEN TO THE BRAKE LIGHTS. FIRST OF ALL IS THE BRAKE LIGHT SWITCH GOOD ? THE ORANGE WIRE FEEDS THE BRAKE LIGHT SWITCH, THE WHITE WIRE PUTS POWER TO THE TURN SIGNAL SWITCH, SO THE LIGHTS CAN BE USED AS TURN LIGHTS OR BRAKE LIGHTS. , PUT A TESTER IN THE WHITE WIRE & PRESS ON THE BRAKE PEDAL. IF THE TEST LIGHT LIGHTS UP, BRAKE LIGHT SWITCH IS GOOD, BY THE WAY THE BRAKE LIGHT FUSE MAY BE LABELED" STOP", THE FUSE LABELED" BRAKE" IS FOR THE ABS SYSTEM. TO CHECK THE TURN SIGNAL SWITCH FOR BRAKE LIGHTS, REMOVE THE PLASTIC COVER FROM UNDER THE STEERING WHEEL, PRESS ON THE BRAKE PEDAL, PUT THE TESTER IN THE SMALL YELLOW WIRE, THEN THE SMALL GREEN WIRE. IF THERE IS NO POWER IN EITHER WIRE, THE TURN SIGNAL SWITCH IS BAD.

Brake light switch would be next.

Rear lights are double filament bulbs one side for the lights other side for the brake/turn signals so it still may be a bulb. Do u have a test light or volt meter you can check to make sure u have power there when brakes or turn signals are activated. Or just try another bulb.