Chevrolet Repair: 1999 pontiac sunfire brake lights, pontiac sunfire, memory wire

Question
My 1999 pontiac sunfire 4door, is really pissing me off. Following the installation of a new radio, my brake lights will not turn off.  Turning off the ignition, has no effect, only dissconnecting the battery has an effect. The brake switch on the break pedal was unplugged and the lights stayed on. I am racking my brains trying to think of how to fix the problem, and I'd appreciate some ideas.  thanks.

Answer
Hi Jodie,

Who installed the radio?  Is it a factory one, or aftermarket?

If the answers are a friend, and aftermarket, you probably have a crossed wire.  Somewhere along the way, a power supply wire was attached to the power side of the brakelight circuit.  There are two wires that supply power to a radio.  One should shut off with the key, the other is the memory...on all the time.  

I think along with the wires that were cut, the one that supplies power to the brake lights were among them.  Then somehow the brake positive wire and the powered up wire are connected together.  The memory wire is the most likely one.   This is bypassing the key and the brake switch.  

The problem is definately related to the radio installation, since that is what you state what happened immediately prior.  I would uninstall the radio, and see if the lights go off.  Then reinstall the radio again.  

Hope this helps.

C J S