Replaced ignition lock assembly used old transponder and switch turns over but no start?'thanks wwwjdh23@gmail.com

Hi, I'm one of the auto experts on RepairPal's Car Genius team! Sorry to hear you are having issues with your Sentra. If I'm understanding you correctly, you replaced the lock assembly but swapped over the original black transponder ring so that you could use the original key/fob In theory this should work. Even though you are not getting a security light illuminated, it does sound like the immobilizer is keeping it from starting. I would start with a battery reset. Disconnect both terminals and leave disconnected for 5-10 minutes and then reconnect. If that doesn't work, your fob/transponder ring may have lost their initialization. You can reinitialize the key fob by sitting in the car with all the doors closed and locked. Then insert and remove the key (without turning it) from the ignition 6–10 times until the hazard lights flash. For the remote (keyless entry) function, cycle the key 6+ times, wait for hazard flashes, then press any button on the fob. If that does not work, you may need to have a locksmith with automotive expertise come out to use specialized equipment to reinitialize the immobilizer chip. Hope this helps! If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554