DarkHorseRacing
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Just putting this here for posterity, in case some inmate goes searching for this later.
I have a 2016 GMC Yukon XL and at about 150,000 miles it started having wonky electrical issues. At first I thought the battery was bad, so I replaced that, but it didnt seem to help anything. So I tried to live with it. Right up until I drove home one night, tried backing into my driveway and suddenly by cranking the steering to lock/limit was able to trigger over a half dozen "Service <this>" messages, including Charging System, Stabilitrack, Steering System, Body Control, etc. In addition to those messages the lights would dim, the gauges and DIC would blip.
Then the next day, I went to start the vehicle and when I got in the vehicle I could see the DIC had power, and the interior lights came on, but when I hit the start button (push start), I got a sudden loud click outside the vehicle and then the vehicle went 100% dead. No power to anything (no lights, chimes, gauges, start button was totally unresponsive, no start noises, NOTHING). So I popped the hood and checked the battery connections and the fuse block, made sure all the relays and fuses were snugly inserted. Wiggled the battery ground seemed to restore the power, so then it was hit or miss if the vehicle started. If it started, it ran, but then the vehicle acted like it had never seen the battery before (despite me not disconnecting the battery in any way) and wanted me to open close windows, etc. If I shut it off, it would sometimes completely die again when I hit the start/stop button.
I thought maybe I had a bad ground so I crawled all over removing, cleaning and reinstalling the ground points on the frame. Seemed to help slightly but was still not 100%. So I found a good article about testing the positive and negative battery cables:
www.gm-trucks.com
Following the above process with a tester, I tested my positive and negative cables with this method. When they say positive cable they mean the little short cable from the battery positive post to the bus/distribution bar mounted on top of the battery in its own little box.
This method states if the positive cable tests to over 100mV to replace it, and the negative to over 200mV to replace it. Well my positive and negative were both over 500mV! So between these two cables, I was losing over 1V of battery power to the vehicle. Not to mention this is hard on the alternator because it cant properly charge the battery with loss like this.
So I'm replacing both of these battery cables. The positive cable itself is a kit with the battery distribution bus, and the negative cable is a three connection ground (battery, frame and engine). On this site: https://www.gmpartsonline.net/v-201...-and-starting--battery-and-related-components its Items numbered 5 and 7. Item number 9 apparently doesnt go bad like #5, so I dont believe it needs to be changed.
I figure this fix will resolve all my issues. I'll report back after I get this done, but I figure if anyone else with a GM product in this year range is having strange electrical issues, start with this test, and with these results to determine if this is the root of the issues.
Also turns out that GM products older than this range have also had a litany of electrical issues and the underlying cause seems to be a history of bad positive/negative cables, so that is something you should still look into even with an older GM product (as far back as 200-2010+).
I have a 2016 GMC Yukon XL and at about 150,000 miles it started having wonky electrical issues. At first I thought the battery was bad, so I replaced that, but it didnt seem to help anything. So I tried to live with it. Right up until I drove home one night, tried backing into my driveway and suddenly by cranking the steering to lock/limit was able to trigger over a half dozen "Service <this>" messages, including Charging System, Stabilitrack, Steering System, Body Control, etc. In addition to those messages the lights would dim, the gauges and DIC would blip.
Then the next day, I went to start the vehicle and when I got in the vehicle I could see the DIC had power, and the interior lights came on, but when I hit the start button (push start), I got a sudden loud click outside the vehicle and then the vehicle went 100% dead. No power to anything (no lights, chimes, gauges, start button was totally unresponsive, no start noises, NOTHING). So I popped the hood and checked the battery connections and the fuse block, made sure all the relays and fuses were snugly inserted. Wiggled the battery ground seemed to restore the power, so then it was hit or miss if the vehicle started. If it started, it ran, but then the vehicle acted like it had never seen the battery before (despite me not disconnecting the battery in any way) and wanted me to open close windows, etc. If I shut it off, it would sometimes completely die again when I hit the start/stop button.
I thought maybe I had a bad ground so I crawled all over removing, cleaning and reinstalling the ground points on the frame. Seemed to help slightly but was still not 100%. So I found a good article about testing the positive and negative battery cables:
How To: Strange electrical issues with 14-18 Sierra/Yukon? Do this test first!
Strange electrical issues? Random codes appearing? Truck going through batteries? May be your battery cables. Here’s how to check them. You’re going to need: -A digital volt meter set to mV -An assistant
www.gm-trucks.com
Following the above process with a tester, I tested my positive and negative cables with this method. When they say positive cable they mean the little short cable from the battery positive post to the bus/distribution bar mounted on top of the battery in its own little box.
This method states if the positive cable tests to over 100mV to replace it, and the negative to over 200mV to replace it. Well my positive and negative were both over 500mV! So between these two cables, I was losing over 1V of battery power to the vehicle. Not to mention this is hard on the alternator because it cant properly charge the battery with loss like this.
So I'm replacing both of these battery cables. The positive cable itself is a kit with the battery distribution bus, and the negative cable is a three connection ground (battery, frame and engine). On this site: https://www.gmpartsonline.net/v-201...-and-starting--battery-and-related-components its Items numbered 5 and 7. Item number 9 apparently doesnt go bad like #5, so I dont believe it needs to be changed.
I figure this fix will resolve all my issues. I'll report back after I get this done, but I figure if anyone else with a GM product in this year range is having strange electrical issues, start with this test, and with these results to determine if this is the root of the issues.
Also turns out that GM products older than this range have also had a litany of electrical issues and the underlying cause seems to be a history of bad positive/negative cables, so that is something you should still look into even with an older GM product (as far back as 200-2010+).
