I just replaced the master cylinder to my 92 Honda Accord EX and the brake lights stay on all the time now. Even when the engine is off and the key is not in the ignition. I bled the brakes. Any ideas on what is wrong and how to fix it?

 

Is the brake pedal fully up to where it used to be before replacing the BMC? Sounds like your pedal may now be lower than it used to be.