Electrical issue

[newTahoeguy]

Intermittent no crank no start issue, been happening for a while usually I cycle the key a few times or throw the jump box on it and it usually cranks over, haven't been driving much due to a frozen caliper but I have recently replaced all calipers and rotors/pads. Back in March at one point had trouble getting it turned over and had a P0513 incorrect key immobilizer code pop up but haven't seen that since. Recently trying to start im losing all power inside cabin, no lights no locks almost like there's no battery.thought it was ignition switch so I replaced that but still getting same issue, also replaced mega fuse still same cuts off, power comes back in cabin after a few hours or overnight not sure exactly on timeframe. I was able to start the engine after these issues by jumping the negative on battery to the front ground on engine block. So the question is now what grounds control the ignition and power to cabin that I can check. 2013 Tahoe Ssv

 

[OBSandaNNBS]

As I was reading your post, I was thinking grounds.
Not sure which one you need specifically, and not sure is SSV has extras, but I know of four. A good place to start anyway

1. Braided strap attaches block to driver firewall.
2. Ground point under the driver's seat on the frame
3 Little ground to radiator support off negative battery cable.
4. Big ground to block from negative battery terminal.

Also, did you do the battery checks like volts off and volts running? Or even better throw a battery tester on it?

 

[Fless]

In addition to what @OBSalsoNNBS suggested: based on the fact that jumping the negative battery post to the engine block made it work, I would say that you have either a bad ground cable from the battery to the block, or just a bad connection. Follow the grounds from the battery and remove and clean the connections.

That negative battery post connection looks suspect, for one.

 

[OBSandaNNBS]

Hey @newTahoeguy , any luck?

 

[newTahoeguy]

After replacing the negative battery cable and cleaning those ground points I haven't had any issues getting it started up, now I have noticed when I put the key in to accessory (the first turn before cranking) I see the battery gauge on cluster go past the 9v mark before it would stop there, hopefully this fully resolves my issue I haven't been driving it much just starting up here and there