GMC electrical issues!

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Apr 11, 2019
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#21
Did you/your dealer try this? Sounds similar:

https://gm.oemdtc.com/TSB/SB-10032396-4179.pdf
Yes and we also replaced all the battery cables and that includes the mega fuse. That actually seemed to help the problem for a little while. But it started acting up again. The cables and fuse have been checked again and that is all still working properly. It seems to have the problems more on hot days, I have no idea why. I just stay in the lane closest to the shoulder so I can pull over real fast if I have to.
 

jsn55

Verified Member
Dec 26, 2014
8,408
8,515
113
San Francisco
#22
This guy also had the problem and found that it was a ground lead:
This is not an electrical problem only. Electrical issues are annoying (take it from one who knows) but this truck is dangerous. Even in the slow lane, losing all power creates a real problem.
 
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Apr 11, 2019
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#23
This guy also had the problem and found that it was a ground lead:
No I don’t think this was tried, thank you so much, I can’t believe I have never seen this video, I have watched a lot of videos. I will have my mechanic try this Monday. Thank you very much for finding this. I hope it works I am desperate to get this issue resolved.
 
Apr 11, 2019
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#24
This is not an electrical problem only. Electrical issues are annoying (take it from one who knows) but this truck is dangerous. Even in the slow lane, losing all power creates a real problem.
Yes I know it’s dangerous, that’s why I have tried everything I have been offered to get it fixed. I have no other way to get to work, what else am I supposed to do? All my extra money has literally been put into this truck. It’s exhausting. I wish I had a way to get rid of it. Unfortunately I have a bank loan for more than I can get out of it, so I don’t think trading it in is an option and I can’t afford 2 car payments. I have to work I have a family to provide for and a home to pay for among all my other bills as well.
 
Apr 11, 2019
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#25
Lkg, while I am definitely empathetic to your situation, please stop driving this truck right now. You are likely to be in an accident serious enough to injure innocent people. A truck as big as your Jimmie could kill a whole family. You have to stop driving it. I may have missed it, but did you purchase from a dealer? What was the blue-book value? When my 2000 Navigator flipped his lid (nothing as serious as what you've experienced) he was 13 with 120K miles or so. My mechanic worked wonders for 8 or 9 years but we finally gave up. His GEM module was causing the issues, it was being dampened by a pinhole leak in the windshield gasket. But the electrical issues never fully went away; that's a Lincoln trait. His value at that age was about $3K. I hope there's an open road for you here somewhere. But you need to stop driving that truck.
I owe $18,000 blue book value is now between 13 and 16,000. Yes I bought from a dealer, they are no help at all and keep telling me nothing is wrong, they can’t find any issues. I literally feel like I’m losing my mind. My family did see it one day and haven’t been back in it since. It’s very frustrating and I don’t know what to do at this point.
 

Neil Maley

Moderator
Staff Member
Advocate
Dec 27, 2014
18,867
17,080
113
New York
www.promalvacations.com
#26
At this point you have no other option than trying to get it properly repaired. Electrical problems are the most difficult to find and fix. This video is a good find and maybe that will fix it for you.

I wonder if the previous owner had any of these issues.

Your post has taught me to use google to check for complaints about problems with used car model I might be considering buying. Over 371 service bulletins for a car is a lot - now I know if I see anything like that to buy another brand or model.
 

weihlac

Verified Member
Jun 30, 2017
1,950
2,040
113
Maui Hawaii
#27
At this point you have no other option than trying to get it properly repaired. Electrical problems are the most difficult to find and fix. This video is a good find and maybe that will fix it for you.

I wonder if the previous owner had any of these issues.

Your post has taught me to use google to check for complaints about problems with used car model I might be considering buying. Over 371 service bulletins for a car is a lot - now I know if I see anything like that to buy another brand or model.
Also recall that GM declared bankruptcy in June 2009, after masquerading as a viable corporation for decades. They had been producing junk vehicles for years. Quality control was not their forte. Sort of like buying from Sears in the last few years.
 
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Likes: krisseye
Apr 11, 2019
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#28
Also recall that GM declared bankruptcy in June 2009, after masquerading as a viable corporation for decades. They had been producing junk vehicles for years. Quality control was not their forte. Sort of like buying from Sears in the last few years.
You are absolutely right, I will google and read everything I possibly can before I ever purchase another vehicle. I got the car fax on this truck, I took a mechanic with me to look at it, it was clean and ran great had no leaks and no signs that if I took care of it, it would run for a good long while. My mechanic also loved it. It makes me sick that only a year later I’m having those issues. in a little over a year I have put 5,000 miles on it and that’s was mostly the first 3 months and then after the battery cables and I thought it fixed the problem, I took 2 short trips about 300 miles away in it. I am gonna try and get a new ground wire ran to see if that helps like one of the videos on here shows, if that doesn’t work, I really don’t know what else to do at this point.
 
Apr 13, 2019
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#29
We own 4 GMC/Chevy SUV’s. One of them(the 2009 GNC Denali XL) had some electrical issues like this. It only seemed to happen sporadically until we deduced that it only happened when my set of keys was in the ignition. My keys were part of a heavy ring of other keys. The weight of the keys was causing issues with the electronics in the ignition. Apparently, according to my mechanic, the weight was causing the well worn ignition to cause electrical errors.(something about the cylinders inside) Once I removed the keys from the heavy ring and just used the fob and the key only the problems went away. Sounds crazy but he was correct. I’m still driving the car with over 160,000 miles on it.
 

Neil Maley

Moderator
Staff Member
Advocate
Dec 27, 2014
18,867
17,080
113
New York
www.promalvacations.com
#30
We own 4 GMC/Chevy SUV’s. One of them(the 2009 GNC Denali XL) had some electrical issues like this. It only seemed to happen sporadically until we deduced that it only happened when my set of keys was in the ignition. My keys were part of a heavy ring of other keys. The weight of the keys was causing issues with the electronics in the ignition. Apparently, according to my mechanic, the weight was causing the well worn ignition to cause electrical errors.(something about the cylinders inside) Once I removed the keys from the heavy ring and just used the fob and the key only the problems went away. Sounds crazy but he was correct. I’m still driving the car with over 160,000 miles on it.
I warn my wife about this all the time. She has more keys on her car key ring I’m waiting for something like this to happen.
 
Apr 11, 2019
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#31
We own 4 GMC/Chevy SUV’s. One of them(the 2009 GNC Denali XL) had some electrical issues like this. It only seemed to happen sporadically until we deduced that it only happened when my set of keys was in the ignition. My keys were part of a heavy ring of other keys. The weight of the keys was causing issues with the electronics in the ignition. Apparently, according to my mechanic, the weight was causing the well worn ignition to cause electrical errors.(something about the cylinders inside) Once I removed the keys from the heavy ring and just used the fob and the key only the problems went away. Sounds crazy but he was correct. I’m still driving the car with over 160,000 miles on it.
Thank you. I have a fob and a few other keys on mine. I will take all but the fob off and try that as well. I will try just about anything to fix this issue.
 

jsn55

Verified Member
Dec 26, 2014
8,408
8,515
113
San Francisco
#32
I absolutely understand how you feel right now. It's gotta be a never-ending nightmare. I can only hope that we keep this thread alive and more people like Alex come forward with ideas. And that one, or a combination, will WORK.
 
Likes: Lkg730