2003 buick century won't start. Ignition switch goes clickety-clickety. Can still lock doors and the lights come on. Noticed the "check engine" light but don't know if it would stay on if engine started. Any clues on this problem? Checked battery water. Problem occurred out of the blue just as I reached home from dealer servicing--TX inspection, oil change & lube, emissions servicing, and brake fluid flushed. Original owner and have 77,000 miles on car--regular dealer servicing.

I don't believe there is a problem either.
Under normal conditions the security light should come on then go off if the correct key is being used.
The problem could be the key switch or the neutral safety switch if it is an automatic trans. There are other possible causes.

sounds to be the starter going bad

it can be the bcm. body control module. it is located under the dash right next to the steering coluum

someone told me to by getting out of the car and locking the driver door with the key, going to the front passenger door and unlocking, then relocking the door using the key. I have to repeat this step 2-4 times and eventually it will start. ?????????
This has nothing to do with it starting !

This is what's happening , Inside the lock cylinder are contacts that read the resistance of the pellet on the key , the contacts are getting worn out . You have two options , replace the lock cylinder or by-pass it all together .
The PASS-Key II® ignition key (1) contains a unique resistor pellet which is idenified by the Body Control Module (BCM) (2). There are 15 different key (resistor) codes. Only one ignition key resistor pellet code will work with each PASS-Key II® theft deterrent system.
Ignition Key Lock Cylinder
The ignition lock cylinder contains spring loaded contacts which make physical contact with the ignition key when it is inserted into the ignition lock cylinder. This allows the ignition lock cylinder to provide the Body Control Module (BCM) (2) with the resistor code embedded in the ignition key.

GM VATS Key Resistor Key Security Bypass
http://www.autopartswarehouse.com/sku/Buick/Century/Standard/Ignition_Lock_Cylinder/1999/SIUS222L.html?apwcid=bngpla

Check for power on the large wire at the starter. There should be power all the time. Check for power on the small wi at the starter. There should be power with the key in the crank position. If both of the above are true than the starter is likely bad.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

You can find the procedure to reset the light here

https://resetoillight.com/buick/oil-change-light-reset-buick-century-1994-1995-1996-1997-1998-1999-2000-2001-2002-2003-2004/

This same thing happened to me in my 1996 buick century just a few days ago. I have the same problem with the door locks and the radio resetting to AM too. I also have the problem of the seats not moving. I think it might be the curcuit breaker or a fusible link. I am not a mechanic, but I do have the repair manual and the mechanics book with the wiring diagrams. If you want me to send the wiring diagram I could do that. I hope that helps. Let me know what you find cause I got the same problem.

It's probably your ignition not being exactly disconnected when you remove the key.Until you get a new ignition (keyswitch),just jiggle the switch with your fingers after you remove the ke7y and see if the dinging stops. my Aerostar has that problem right now. don-ohio

Time to wander through the spaghetti of wires and contacts with voltmeter looking for a closed circuit to ground. Sounds like the radio is where to start.

METHOD 1 - NO TOOLS REQUIRED

1. Sit in the vehicle driver's seat.
2. Remove the ignition key from the ignition lock cylinder.
3. Close all of the vehicle's doors.
4. Press and HOLD the door "LOCK" switch to the "Unlock" position.
5. Insert and remove the ignition key twice (without rotating the ignition lock cylinder).
6. Insert the ignition key a third time leaving the key in the ignition lock cylinder. The ignition must be in the "OFF" position.
7. Release the door "LOCK" switch from the "Unlock" position (three fast chimes will be heard when the remote control door lock receiver enters the programming/diagnostic mode).
8. Press and HOLD the transmitter "LOCK" and "UNLOCK" buttons simultaneously for at least 12 seconds . Two fast chimes will be heard confirming successful programming.
9. Repeat step 8 for each additional transmitter to be programmed.
10. Remove the ignition key from the ignition lock cylinder