My driver side brake light will not work unless I turn on the turn signal for a second then it works for awhile and I have to do the same thing over. I have a 1999 GMC Jimmy 4dr 4.3L

check wiring for short

On most models the brake light circuit runs thru the turn signal switch. The third brake light does not. So it could be a problem with the turn signal switch.
A ground problem would also affect the parking lights.

take it to a body shop

turn on your hazard flashers then off again some times dirt gets arround this switch and causes funny things like that to happen. good luck

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.

Sounds like you need to replace the drivers brake/tail light.

you replaced the bulb with the wrong one i.e. a two filament bulb with a one filament bulb

I do not know what you have already tried, but let me start at the most basic first, and work up the list of possibilities. OK?
Have you checked the bulb on that side? The tail light could still work, but Brake/Signal part be out.
Assuming that did not fix it, my next shot would be at the turn signal switch. It is what separates the brake lights from the signals, and would be next in line, unless you can see an area where the wires are damaged underneath.
An easy way to check all this quickly, is to turn on the Hazard Flashers. All 4 should blink, of course, and if they do, the turn signal switch most likely is bad.
Hope this gets you going!

If it is the turn signal flasher it should be located in the Front seating area, driver side, driver side of steering column, behind instrument cluster, mounted in convenience center. It is possible that there could be a bad ground too. Flasher would be the first thing to check.

try changing the bulb. it could be the wrong one.make sure its the right one buy calling the parts store. good luck