Car Electronics and Lights
Headlights Tail and Brake Lights
Oldsmobile Cutlass Supreme

Why dont your brake lights work when all the fuses and bulbs are good in your 97 cutlass supreme?

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Answer

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Wiki User
09/13/2011

If you are sure the fuses and bulbs are good --- there are only a few other thing that will not make your brake lights come on. One is because your brake light switch isn't working. Yes -- there is a switch that makes contact when the brake peddle is pushed down, which than lets the electrical current run to the brake light bulbs. Or wiring from the brake light switch to the brake lights have come unplugged or been damaged, or you have lost the ground to the brake light blubs (highly unlikey) if you lose the ground, other lights should either not be working in the back of the car or coming on dim etc... The Break light switch is either on the master cylinder and works off the fluid pressure when you apply the brakes, or attached to the shaft of the brake pedal itself. Find the switch itself, just look at the master cylinder and see if it has any electrical wires attacked to something on it, or look up under the dash and follow the break pedal shaft and see if you find a switch with wires attached, once you find the break light switch, you should find either two or three wire, going into the switch. If the switch is on the break pedal shaft, make sure that the little nipple that sticks out of the switch isn't broken off, you should be able to reach up under there and push the nipple in and out of the switch, have someone watch the break lights to see if they go on and off, if they do, than the switch has come out of allignment or the nipple has broken and you are pressing on what left of it, and its not long enough to work off the pedal. Next step if it still doesn't work, (and this part also applys to a break light switch if its attached to the master cylinder), disconnect the wires to whichever switch you find, making a note of how they were hooked up so they can be put back on in the right place, once the wires are disconnected from the switch hold the metal ends of the wires to each other and see if the brake lights come on, if they do, than the switch itself is bad and needs to be replaced, (alot of break light switches can be found at Pep Boys, Auto Zone etc...) if the lights still don't come on, than there is a problem with the wiring running from the front of the car to the brake lights. With a test light you can trace the wiring down and find out where the break is in the wiring , or find a bad connection that is causing the problem. Sounds like a lot to do -- but its pretty simple to test the break light switch, tracing the wiring can sometimes be a nightmare. Who knows, you may find the break light switch and find a loose wire on it, it also could be that easy. Hope this helps :-)