2015 Yukon electrical issue

[Seanjordan20]

I have had an electrical issue for some time. The problem has occurred 4 times since I’ve owned the truck. 15 Yukon Denali 70k

The first time it happened the auto start would not work and figured it was just a mishap since after a few minutes it worked as normal. The next time it happened a new battery was installed not OE because GM would not warranty the battery a couple weeks after 3 years. I figured if GM doesn’t warranty there battery just because a few days after the warranty why would I pay $$$ for a battery that gets only 3 years. So I went with an Advance Auto platinum battery that has a 5 year warranty.

Fast forward to now. I went on a road trip and came back yesterday. My side step did not come down and I didn’t think anything of it. This morning I lifted the tail gate and was pulling stuff out and the dome lights started flickering and the truck started clicking on its own, then the truck went dead. I couldn’t unlock the doors or no lights. I had to use the key to open the drivers door to get the hood open. Once under the hood the positive battery terminal was real hot melting the plastic and burned me when I touched it. Went to get the battery tester and everything started to work as normal. It was odd but I still checked the battery and the health was at 100%.

I do all the work on all my vehicles and this does not seem to be anything to force me to take it to the dealership. I only checked the battery cables at the battery and when the wife gets home from work I will check the grounding points. Has any one had this happen or know what to check if the points are good. The positive fuse box is in good condition and and all cables look good and tightened down. I’m thinking if I do not see anything visually wrong I’m just going to replace both cables with the positive fuse box. Any suggestions would be great.

 

[Big Mama]

Checking all the grounding points is a good start. Usually a bad ground doesn’t get the positive side that hot but everything else you’re describing does

 

[Doubeleive]

a hot positive would be a sign of a short somewhere, I agree with changing the cables, when you get the new cable's take a meter and test the resistance of the old cable's versus the new cable's and see if that was the issue on previous model trucks the battery cables have been reported to corrode (from the inside) I don't know if this would still be a issue on the newer trucks or not. at any rate it is a good starting point.

 

[kiboater]

I would really know if you find out what is causing this. I have a 2016 Yukon Denali and once last year and again a week ago the battery had gone stone dead. First time I blamed it on a bad battery but this time I kept the old battery and was able to bring it back and after a lot of charging, it now test good. There is no drain on the battery now but I think there must be some intermittant issue that draws the battery down so low that it is incredably difficult to recharge it. The 8 month old Delco OEM replacement only shows 3 volts. But I was able to eventually recharge it which makes be believe something is causing the draw down.

 

[Seanjordan20]

I have done some research and have purchased the updated positive harness (84528825) and updated cable distribution fuse block (84354716). Apparently there was some issues with the old parts. I will hopefully get them in next week and install them. Will update after I test the harnesses and install.

 

[Seanjordan20]

The new parts purchased are below:

84354716 Block
84634109 Cable
84528825 Harness
23119639 Positive

I tested the cables and found an issue with the ground cable at the support mount location. It was very oily and dirty. I replaced all the cables and at the mount location I cleaned it up real good then I took a dremel at it before bolting the cable.

I also tested the cables when removed and they tested good. So nothing was wrong with the cable it was the mounting point. I wanted to get the newer model cables because they covered all exposed wires.

I’m going to test my alternator now to make sure it is good because something made the positive cable hot enough to melt the cover but I don’t know what at this point. The car was off so I’m thinking either the fuse box or alternator (reaching on the last one). I’m going to remove the fuse box to see if I see anything out of the ordinary some time this weekend. I will post an update once tested.

Who knows it might of been the battery but it is barely a year old.

 

[Seanjordan20]

I checked my engine bay fuse box and found nothing wrong. Since changing everything the truck has been fine. One thing I have noticed is the voltage from the alternator is real low. I think having a power management system in the truck doesn’t work well with an AGM battery. Over time I will see how it goes.
I do understand how the system works but the battery voltage needs to be higher to start a 6.2 and this is probably why I have issues starting it at times. I will post back if I notice anything out the ordinary. As of now I’m considering my issue resolved.


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[Big Mama]

Great that’s the goal

 

[Seanjordan20]

I forgot to upload my voltage meter pic. It has gone lower but stays in the grey area.




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[Big Mama]

I’m no expert on new rigs but I’d guess they need more juice than my 07. Mine runs around 14 no matter the rpms. I think they put the ideal number top center of the gauge to make it easier to check. I’d think yours sb 14 too. On a side note I did a full system test and it showed my alternator was too hot though it works fine. Looked at it and found some wire coating cracked. I mention that bc heat can keep it from performing well.