On my 1995 olds cutlass supreme, both rear brake lights dont work simultaneously, then sometimes they do, checked fuses but they are ok, bulbs are still good, what could be wrong?

Step 1:

what i would do first is check your fuses first

Step 2:

then if fuses are okay then check the light bulbs in the rear light assembly

Step 3:

if problem still exist then go to the brake light switch on the brake pedal and replace it

usually brake switch failing causes this but the flasher relay cant be ruled out providing wires or the bulb socket arent burnt or shorting out

If all the bulbs are good, it could be the multi-stalk arm switch. Jiggle the arm all around, the switch could be dusty, or lightly corroded.

If all else fails pull all fuse's that you can't check when installed.

check voltage from brake switch to signal light switch, if good the the signal switch is probably bad

Do the brake lights work? If the brake lights work then you probably need a new turn signal flasher,if not then check that all the bulbs are good,front and rear and check for a blown fuse...

You probably have a bad brake light switch. This switch is located on the brake pedal arm or a bracket next to the arm. This switch activates the brake lights when the pedal is pushed. You can check this by turning on your turn signals or warning flasher if your light flash in the rear. Your bulbs are good so this will bring you back to the brake light switch.

check the bulb... reccomend replacing brake light bulbs if they still don't work check the fuse for the brake lights

If the bulbs are good, check for a bad local grounding point.

I have a 1987 Cutlass Supreme and the brake lights wouldn't work. When I moved the tilt steering to a certain position they worked.

Hi! Have you checked the brake light switch? usually located at the top of the footbrake pedal, it is a plunger type and should have two wires going to it? if faulty try bridging the connection/wires for a test! have someone watching your lights to save jumping in and out of vehicle.
Merry Christmas!
Paul 'W'
Onyer~EDson(:0)~[><
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