Truck dies over night

[ItsYeBoi_Pena]

My truck, 02 silverado  has been dying for a couple months now and I can’t figure out why. at first i thought it was the sound system in it so i took it all out, subs, radio and amps but still dies. I then believed it was my headlights because they tend to stay on after the truck is off (I have to hit the dome override button 3 times for them to turn off) so i disconnected those too and nothing. I have an xs d3400 battery that isn’t even a year old, could that be my problem? or maybe my alternator which is a mechman 250 amp?

 

[richard wysong]

Could be either, have the battery and alternator tested at the parts store. make sure they test the diodes in the alternator. If that's not it then time to do a parasitic draw test cuz it could be a million things