E_Walk1989

So this is going to be long as im going to try and include as much info as i can.
I have a 2010 Equinox LTZ. I love this car. When i purchased it i quickly found out that the sunroof was leaking. Every time we got a heavy rain my glovebox would have a puddle. Fixed the leak o more puddle. Problem solved? Yea right, the car developed a ‘ghost’. The headlights, AC, radio, door locks, dash lights and gauges and steering wheel controls would randomly flash on and off as the car was running. Not like once or twice but more like a strobe light majority of the time. This went in for months, i had a cpl people look at it and track down wires and clean grounds but nothing seemed to help. Then one day it all just stopped and has yet to do it since. 🤷🏼‍♀️ Fast forward about 6 months, time for maintenance. New plugs, oil change etc. leave from having that all done, car runs like its-brand new! Stop at walmart. When i go to leave, the car wont start. Almost like it’s dead but everything still comes on and lights up. Snd it’s been DOA every since. Batterys good, starters good. Nobody can seem to find the problem!! Any ideas or thoughts as to what this might be?