Hey guys,I just aquired a 70 cutlass supreme and when i got it the guy said the tail lights stay on even when the engine is off,what is going on? The wiring looks to be original no cuts or spliced up wires.all conections are fine,but everytime i turn the car off my brakelights stay on unless i disconnect the battery, what could be the problem?

 

It could be the brake light switch. Just adjust it at the brake peddle and see if that works.

 

I think hamm36 is right. Disconnect the plug from the switch. If the lights go out you have found the problem. It is probably just the adjustment which is simple to fix.

 

X3 on the brake switch. Start with the simple things first and hope to find it quickly! Look under the dash, to the left of the steering column and you'll see a switch that has a button that is depressed when the brake pedal comes up. That has the two wires hamm36 mentioned running to it. Good Luck! John

 

Does sound like the brake light switch is either bad or not adjusted properly? Look under the dash at the brake pedal lever and see if the switch is depressed al the way when the brakes are off. If not just push the switch housing towards the pedal until the button depresses. It's a fricton fit between the brake light switch housing and the bracket and should stay in position.
If it stays on it could be a bad brake light switch, wire plug connector not attached to the switch, bad connection.

 

FYI, the brake lights are powered all the time, not just when the key is on. Adjustment of the switch is easy. Disconnect the wires from the switch. Hold the brake pedal down. Thread the switch in several turns. Now pull up on the brake pedal until it hits the upper stop. Connect the wires and you're done. If this doesn't fix the problem, you may need a new switch.

 

The brake switch,that makes perfect sense, ill adjust it when i get home,thanks