I have a 200 montie Carlo ss I put a new starter in and it would not start and I found out that my tumbler was broken to and so I put in a new cylinder lock and key I tried to start the car up and the car won’t start but my dash light turn on what do I do

 

You will need to relearn the VAT's security system. The information should have came in the box with the new key and tumbler. Otherwise Google relearn security for a 2000 Monte Carlo and follow procedure. Good luck.