2016 Yukon/Electrically dead with new batt

[tmcdrwww]

I have one for you guys just to bounce ideas around.

2016 Yukon SLT
55k miles - Stock from factory.

Last week (11/12) my wifes Yukon was dead in the morning and this battery was replaced 08/30/21. Thinking it was just something left on I swapped it out on warranty and everything worked fine - Nothing unusual.

This morning - 5 DAYS LATER - (11/17) - My wife starts up and drives roughly 15 minutes to drop for daycare. ( While driving she turned on one of the LED cab lights and she noticed it was flickering, she then turned it off. ) After arriving at her drop off she turned off the Vehicle and within 5 minutes it was Electrically dead. I immediately thought alternator but after Metering out the Batt its holding 12.4V. However - Nothing in the interior lights up/No dash display/No odometer. It will not Jump and we noticed the Negative Batt cable is hot to the touch. There are no blown fuses found as of now.

Bad ground?
Short?

I've read about the battery cables being crap, but also that the flex fuel vehicles cannot be jumped? Anyone come across this?

 

[Bill 1960]

Heat means high resistance so first impression is a bad ground. Is it hot the length of it or just at one end or the other? A point source of heat is a clear indicator of the trouble spot.

 

[Doubeleive]

most likely you need new battery cables, they go bad internally and like to burn at the starter connection as well
personally I would replace the whole shebang, battery ground, battery top fuselink/cables and the one going to the alternator, I don't recall what is all included from gm I replaced mine on my 18 already. It was under $200 for everything, closer to $130 or so I think, but I get a discount from my dealer so it might be a little more.

 

[OR VietVet]

Agree with @Bill 1960 and @Doubeleive and would want to make sure all connections at starter solenoid are clean and tight. Double check the attaching point for the negative NEW cable.

 

[tmcdrwww]

From what I could tell during the quick run through is that the heat continued throughout - We left the vehicle in place and I will return for it later tonight when I can really dive into it.

I will start tonight by verifying and cleaning all connection points - Chassis ground, Engine ground, starter solenoid and battery? Any hidden points that would easily be overlooked?

In the meanwhile I will order parts for piece of mind - The question that immediately comes to my mind is: Is there an alternative Part that can be ordered that fixes the known bad issue? I don't necessarily want to replace this with GM parts that are going to just blow at random. Especially if this is my wife's main transport and she has our daughter in the truck.

 

[Doubeleive]

From what I could tell during the quick run through is that the heat continued throughout - We left the vehicle in place and I will return for it later tonight when I can really dive into it.

I will start tonight by verifying and cleaning all connection points - Chassis ground, Engine ground, starter solenoid and battery? Any hidden points that would easily be overlooked?

In the meanwhile I will order parts for piece of mind - The question that immediately comes to my mind is: Is there an alternative Part that can be ordered that fixes the known bad issue? I don't necessarily want to replace this with GM parts that are going to just blow at random. Especially if this is my wife's main transport and she has our daughter in the truck.

they have updated the cables so theoretically it should not occur again, the only other alternative is custom made cables, not sure what you have in your area but there is a battery dealer her in my town that will make custom cables at there store. doing that would probably require taking in the old cables so they could make them the correct length and correct sized/type connectors.
I noticed when I replaced mine the starter cable for instance was wrapped better with heatshielding, the old one had barely any and lots of glue on it.

 

[OR VietVet]

You could also have an intermittent diode problem internally in the alternator but when I have seen them fail, it drains a battery but have never heard of causing the draw so bad that cables heated up. But because of the possible cables problem, that could damage the alternator.

 

[tmcdrwww]

I appreciate all the insights you've provided.

I am currently at work and my buddy is looking after it momentarily and he said it fired right up after it had been sitting for awhile. Now it looks like the issue is it will die after warmed and running. Sounds like the vehicle is sensing the overloaded battery cables and killing itself for protection? Either way they will be getting replaced.

 

[Doubeleive]

I appreciate all the insights you've provided.

I am currently at work and my buddy is looking after it momentarily and he said it fired right up after it had been sitting for awhile. Now it looks like the issue is it will die after warmed and running. Sounds like the vehicle is sensing the overloaded battery cables and killing itself for protection? Either way they will be getting replaced.

that's a possibility, when the cables heat up it creates electrical resistance and then will not provide the amps needed for the vehicle to run, same thing as replacing a battery cable with a tiny wire.

 

[tmcdrwww]

Just an update to close out the post for those on search issues.

Replaced ALL battery cables and grounds. So far issue has gone away - only time will tell.

Thanks again to all who helped.