Have you noticed your headlamps blinking or flashing while driving or when the car is completely shut down?

I had these same symptoms with my 02 SS with the clicking noises and blinking lights. My key fob also needed to be replaced but did not fix the problem.

Eventually the lashing lights would kill my battery by the next morning, so I would disconnect it every night.

I did some research and found that the BCM was most likely to blame. I had my uncle put in a new one in but the dealership had to program it. I believe the BCM was about $100 at AutoZone and then $50 to program it, but I saved a ton of money not letting a shop figure it out lol this was about 4 or 5 years ago so I'm not sure how much they go for now.

The BCM fixed all of the bizarre electrical issues for my Monte. When ever I hear someone say "electrical problem" with their Monte, I automatically think of the BCM haha

I hope this helps. Good luck!

 

After almost 2 weeks on the new battery, everything seems to be fine. No clicking or flashing lights. I guess it was a bad battery.

still haven't used my key fob, and i keep the usb charger unplugged when the car is off.

 

I found for all my Chevy's that if I left my USB chargers plugged in when the car was off, the battery would drain super fast. I've always had a habit to pull them out of the port because I've ran into dead batteries due to this more than once. I've noticed different car manufacturers disable the charging ports when the car is off, but Chevy has always left them on.

 

Give me the Chevy approach any day. Far better to unplug a cord overnight than to leave the keys in the ignition to charge a phone, like I need to in my wife's Tundra.