Lately, whenever I have withdrawn the key from the ignition on Superblue, I have not been hearing that usual loud “snap” sound, esp. when the weather is cold. 
I then open the door to exit and the warning chime keeps going off. I’m almost afraid to leave the vehicle in that condition, for fear it may run the battery down by the next a.m. when I return, for fear that some electric circuit(s) is not shutting off like it should. 
Any idea what is going on, and how do I fix it? 