Sitting watching television at about 11pm with the sliding glass doors open. I heard a noise outside. I go to investigate and I hear a cracking/popping sound coming from the outside ac unit and the smell of electric burning. The unit was not turned on when this happened so therefore was not running. I immediately turned off the power to the unit. Any idea of what this could be and what I might be looking at? I am a bit befuddled especially since the unit was not even running at the time. Any advice would be appreciated.

By the way. No heat pump involved here.

Hi parker and welcome, the sound could have been a rodent chewing on the wires, inspect them carefully. Good luck