On the driver side underneath

Hello, This may be an issue with your security system, including the key, the ignition switch, or a number of other potential causes. Since you have already replaced the battery, I encourage you to examine the battery terminals for corrosion, cracks, or any sort of damage that would lead to a loss of conductivity. Next, check all of your fuses. You want to make sure the ignition fuses (ignition switch, not ignition spark) are not blown. Also, check to see if your relays are clicking when you power the ignition switch on.