3373JB

Hey everyone, I’m new to the forum and this is first for me so please bare with me for the long post. Truck: '14 Silverado 5.3L 1500 So, I have a bit of a issue. I have had my truck a little close to a year. I started to notice the starter was taking a moment to crank over from cold starts recently. So the other day I came out to move the truck and it wouldn’t crank over. I pulled the battery and and starter and had them bench tested ( starter and battery issues over the years with other cars i have owned and I just wanted to get things done with as few trips as possible) both are 100% good. I re-installed everything and then boom, no dash lights, chime once I turned the key. No dash lights, no door open ping, no headlights, dome lights or tail lights and no crank. There is power to lock the doors with the remote fab and only a headlight and hazard light flash when I unlock/lock the truck I can hear the click from the relays as well but no juice to start. I’ve checked and cleaned the negative battery cable ground leads and still nothing. Fuses are fine and no visible-notice of corrosion. I even pulled the dash apart to check the ground wires by the windshield and nothing. Need some direction on this one since it is electrical. I’ve read that the BCM has had some symptoms like mine and also the negative wires from the battery wearing out and needing to be changed. Any feed back helps and thanks in advance! JB