Q: Car not starting and alarm not working.

Having your car not start after having a brand new battery installed can be a frustrating experience. Even though the battery is indeed new, the fact that there is no start and a non functioning alarm in your Cadillac DeVille, points me back to the battery. Again with limited information I have to fall on my experience, based on what I have most often seen working in the field.

Since a brand new battery was installed recently, it leads me to wonder if this replacement was needed after a bad battery was discovered due to your DeVille sitting overnight. If this was indeed the case, your Cadillac is experiencing what is called parasitic drain. This is when one of the electrical components in your cadillac draws power away from the battery when the key is out of the ignition. I suggest having your vehicle jump started next. You may have to leave the jumper cables connected for several minutes with the other vehicle assisting in the jump to help charge your battery. If your vehicle starts up and stays running after you disconnect the jumper cables, it is very likely you have a parasitic drain. If you are still unable to start the vehicle, the problem may lay elsewhere. Enlisting the assistance of a certified technician will be able to inspect whether a parasitic drain is the problem or if your Cadillac is experiencing a different issue.