GMC electrical issues!

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Apr 11, 2019
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I have a 2008 GMC Sierra Denali 1500 with 130,000 miles. I know that it’s not brand new but I have only owned it a year. After a few months of having it, it started acting crazy! Lights flash on and off, radio goes on and off, all the lights on the dash come on at once, doors lock and unlock continuously, it loses all power at any given time, and it breaks on its own at any given time, I have had more than my fair share of close calls, driving 70 down the expressway and the breaks slam on all by them selves, lights going completely dark late at night... I have had it looked at more times than I can count and no one can ever find what’s wrong with it or what causes it to do this. I have replaced the alternator, and the battery cables and it’s back to doing the same thing. GM says it’s not a common problem, but if you look online thousands of people are having the same issues. GM says it’s something I did and just a coincidence that other people are having this issue. I know it’s not a brand new truck but it’s new to me and I paid a lot of money for it. I just want it to run right and be safe for me and my family to get where we need to go.
 

Neil Maley

Moderator
Staff Member
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Dec 27, 2014
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#2
Apr 11, 2019
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#3
I would understand what your saying if I was the only person having this issue, but I’m not. There are a very large number of people with the same year GM as me having the same issues, it’s on other GM products as well, the Escalade, Yukon, suburban, Acadia, Silverado, and others. My thing is it took 10 years to get a recall on the ignition switch recall that killed some people, I have money invested in this truck and it’s unfortunately my only transportation, I’m driving it to work every day with these safety issues, is it gonna take something serious happening before GM will consider it a problem? I’m not asking for reimbursement on what I have had done to try and fix the issue, I’m simply asking that they fix the mistake that was obviously a manufacturer defect. I’m asking GM to stand behind the product they make, and make things right. 11 years on a vehicle with 130,000 miles is not bad and should have a lot of life left.
 

weihlac

Verified Member
Jun 30, 2017
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#4
I would understand what your saying if I was the only person having this issue, but I’m not. There are a very large number of people with the same year GM as me having the same issues, it’s on other GM products as well, the Escalade, Yukon, suburban, Acadia, Silverado, and others. My thing is it took 10 years to get a recall on the ignition switch recall that killed some people, I have money invested in this truck and it’s unfortunately my only transportation, I’m driving it to work every day with these safety issues, is it gonna take something serious happening before GM will consider it a problem? I’m not asking for reimbursement on what I have had done to try and fix the issue, I’m simply asking that they fix the mistake that was obviously a manufacturer defect. I’m asking GM to stand behind the product they make, and make things right. 11 years on a vehicle with 130,000 miles is not bad and should have a lot of life left.
11 years and 130,000 mi on a GMC vehicle is end of life. If you have not done so, take it to a good local independent mechanic. If they cannot find the problem you may be out of luck.
You can appeal to GM as above but your vehicle is still an old high-mileage vehicle. If there is not a recall you will have no recourse if GM will not help.
Put your VIN into this web site: https://www.nhtsa.gov/recalls
You can also put "general motors" into the search box in the upper right of this page and see what other similar problems people had posted about.
 
Likes: Neil Maley

Neil Maley

Moderator
Staff Member
Advocate
Dec 27, 2014
17,074
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www.promalvacations.com
#5
Contact GM using the information I gave you- you have nothing to lose by asking- the worst they can say is no but your letter might end up on the desk of someone that makes an exception.
 
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Dec 23, 2018
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#6
A bad ignition switch can cause some strange symptoms. As far as braking by itself, you could disconnect the ABS.

I agree with finding a good independent mechanic. Does it act up frequently enough that a mechanic can duplicate the problem?
 
Sep 27, 2017
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#7
This sounds really dangerous, and I'm sure you would ditch it if you could. If there is any hope at all, I had an older Chevy vehicle that was put under a service bulletin (like a recall) and the threshold was 140,000 miles. But while it's a future possibility that GMC COULD flag it for a service bulletin, it's not reality for you right now, and you have to ask is it worth the safety of yourself and others to be driving around in it?
 
Sep 20, 2018
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#8
It's an 11-yr-old vehicle with over 100k on the 'clock that you bought used. It'd be nice if it didn't suffer basic electrical issues at this point (I'd say a modern vehicle is "expected" to last at least 200k these days), but the obligation of the manufacturer to fix it for free (absent a recall) has long past. They did "stand behind" the vehicle; that's what the New Vehicle Warranty is for, and that's been over for a long time.

What did these "thousands" of other people with the same issue do to fix the problem?
 

Neil Maley

Moderator
Staff Member
Advocate
Dec 27, 2014
17,074
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New York
www.promalvacations.com
#9
I checked online for the complaints. The NHTSA has 371 complaints starting in 2008 but I don't see any that reflect all the problems you are having. There are many showing different problems with the electrical system. The NTHSA has two investigations - one from 2008 that was recalled so the previous owner should have taken care of that and the other about electrical fires in 2008 that was closed. There were 314 technical service bulletins, the last in 2017 for fixing cruise control. I also didn't see a recall for the ignition switch, only one in 2008 for other electrical issues. Maybe I am missing something.
 
Jul 13, 2016
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#10
I would understand what your saying if I was the only person having this issue, but I’m not. There are a very large number of people with the same year GM as me having the same issues, it’s on other GM products as well, the Escalade, Yukon, suburban, Acadia, Silverado, and others. My thing is it took 10 years to get a recall on the ignition switch recall that killed some people, I have money invested in this truck and it’s unfortunately my only transportation, I’m driving it to work every day with these safety issues, is it gonna take something serious happening before GM will consider it a problem? I’m not asking for reimbursement on what I have had done to try and fix the issue, I’m simply asking that they fix the mistake that was obviously a manufacturer defect. I’m asking GM to stand behind the product they make, and make things right. 11 years on a vehicle with 130,000 miles is not bad and should have a lot of life left.
Did you do any research before buying a 10 year old truck? Did you have an independent assessment prior to purchase? Did you check CarFax? Years ago, before computers in cars/trucks, a 10 year old car might have some life left in it. But nowadays, 10 years old is end of life, as one poster put it.
 
Feb 12, 2019
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Apr 11, 2019
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#12
A bad ignition switch can cause some strange symptoms. As far as braking by itself, you could disconnect the ABS.

I agree with finding a good independent mechanic. Does it act up frequently enough that a mechanic can duplicate the problem?
I had it for about 3 or 4 months before it started to act up. It has only done it once in front of a mechanic, and it didn’t last long. It doesn’t show any codes. He replaced the alternator, I thought it was fixed and 2 days later it was doing the same thing. It could last for a few seconds and just doing one thing or it can last until I pull over for a bit doing everything that I mentioned all at the same time. It has a clean car fax and everything else about the truck is excellent.
 
Apr 11, 2019
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#13
The problems sound similar to what I heard about vehicles that were flooded since one of the biggest things they mention is problems with electrical systems. Just a guess though. The consumer report link below has a couple options to check your VIN to see if that might be the case.

https://www.today.com/video/how-to-protect-yourself-from-buying-a-flood-damaged-car-1326740547729
https://www.consumerreports.org/buying-a-car/beware-the-flood-of-flood-cars/
I have checked everything to see if it’s ever been involved in anything and this truck is as clean as it comes. Nothing has ever been reported wrong or damaged on it.
 
Apr 11, 2019
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#14
Did you do any research before buying a 10 year old truck? Did you have an independent assessment prior to purchase? Did you check CarFax? Years ago, before computers in cars/trucks, a 10 year old car might have some life left in it. But nowadays, 10 years old is end of life, as one poster put it.
It’s the biggest purchase on a truck or car that I have ever made. I had everything done and investigated before I bought it. It took a few months for it to start doing this. When I take it to get it looked at it never acts up and every mechanic that I have ever seen tells me there is nothing wrong with it and runs like new. I know it’s older with 130,000 miles but I owe 18,000 dollars on this thing and can’t afford to keep paying for it and paying a mechanic, I have to drive it to work every day and it’s a gamble every single time. My family won’t got in it and call it a death trap. I just want this issue fixed.
 
Apr 11, 2019
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#15
It's an 11-yr-old vehicle with over 100k on the 'clock that you bought used. It'd be nice if it didn't suffer basic electrical issues at this point (I'd say a modern vehicle is "expected" to last at least 200k these days), but the obligation of the manufacturer to fix it for free (absent a recall) has long past. They did "stand behind" the vehicle; that's what the New Vehicle Warranty is for, and that's been over for a long time.

What did these "thousands" of other people with the same issue do to fix the problem?
Some said replace the alternator, I did and it didn’t help, some said replace the battery cables so I did, it didn’t happen for a good while after that, then all the sudden it started again. If all these other people weren’t complaining about the same issues I wouldn’t think it was a manufacture defect, but obviously it is if people are having the same issues, that’s not some kind of coincidence. I spent a lot of money on this truck that’s 10 years old and still paying on it and paying to try and fix it. All I’m asking for is an answer to why this is happening to my vehicle, and others of the same make.
 
Apr 11, 2019
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#17
Can you point is to where you are seeing all these issues? I searched google for a good hour today and I couldn't find any of this. Did you actually take it to the dealer to be looked at?
Yes I did and they can’t find anything wrong. They tell me it runs great and don’t see any issues. I told them to keep it a few days and drive it around, they wouldn’t do that. Search 2008 GMC Sierra Denali 1500 common problems, or electrical issues and all kinds pop up. There are even a few videos on you tube of it happening while people are driving.
 

jsn55

Verified Member
Dec 26, 2014
7,926
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San Francisco
#20
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.
 
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