I had something unusual happen tonight and wondered if anyone here had any clue of the cause. I have a 04 SS and all of the electronics went out then came back on. Lights, radio, cluster, everything but the engine. It only lasted a second or 2 but when everything came back the clock had reset and the security light was on. I shut the car off and restarted it at the next red light and the security light went out. Any suggestions or input would be welcome.

 

Most of those things and security are controlled by the BCM.
I'd keep an eye on it to see if it continues to happen. BCMs can be purchased on Amazon new for $120 and some auto part stores sell remanufactured units for about $100 after core exchange. If you're handy with soldering you could check the solder connections on the BCM board for the plug and reflow any bad joints with some more solder and flux.

If you do wind up having to replace the BCM they do need to be dealer programed.