Cadillac Repair: Security system on Seville, cadillac sts, lock cylinder

Question
I have a Cadillac STS.  Last weekend I got in it and put the key in and the security light came on solid and everything shutdown.  No door locks, lights or anything.   Later I tried again and turned the key and heard a click under the hood but the security light and other dash indicators that were on went from dim to dimmer.  Am I having problems with the security system. Oh, by the way I tried a second key the second time.  Is the sensor for the key resistor pellet bad or what?  Will this problem shutdown the entire electrical system?

Answer
Hi Mike, Sounds like one of the small wires comming from the ignition lock cylinder has broken in 2 and you will need to replace the ignition lock cylinder and keys. If you don't care if the special key starts the car then all you have to do is measure the key resistor and go to radio shack and buy a resistor close to the same reading and cut the wire at the bottom of the steering column and wire the resistor in place. Then the engine will start up. Bill