Cadillac Repair: 99 caddy sts, car wont start, work car

Question
just replaced battery and starter- lights and evrythign work car wont start up could it be the alarm system? or what dopes it sound like?

Answer
Do you hear any engine noise when you try and start the engine or do you hear NOTHING ?.

If all you hear is nothing or just a click when you turn the key, It is most likely a security systems failure.

Do you get a message in the message display showing: "WAIT 3 MINUTES and TRY TO START AGAIN ?.