Jump to content

2005 GMC Sierra 1500 Electrical Issues

Jordan Walter
 Share

Recommended Posts

Jordan Walter Enthusiast

Jordan Walter

Posted
Posted

I was having electrical issues on my 2005 GMC Sierra 1500, which is at 197,000 miles. The issues were things like pulsing lights (interior and exterior and low voltage fluctuation (14.0v to 11.8v) so I replaced the alternator with a premium 160amp remanufactured one from CarQuest. Now my voltage seems high, sitting at 14.9v-15.2v during idle. The pulsing went away, but now it pulses when I rev the engine. I will leave it at about 1500 RPMs and it will steadily pulse until I release the gas. Is this an issue with the alternator or something else?

EightTrackHits Enthusiast

EightTrackHits

Posted
Posted

Is the battery light still on?  I had an alternator problem with a Trailblazer, battery light would not go off, connections were tight.  I checked continuity of all the connections to their next assembly and found that the wire carrying the pulse width modulation signal (PWM) was open.  The fault was fairly close to the connector and I fixed it with a pigtail I cut from a unit in a junkyard.

 

You mentioning pulsing also makes me wonder if it is in the PWM circuitry, but if it is, it is likely not an open PWM wire as that would cause the alternator to give max output all the time.

 

Good luck and let us know.

 

Another member had similar problem, but he never followed up with his fix: 

 

Mr. Z71 Enthusiast

Mr. Z71

Posted
Posted

Jordan... just for the heck of it run a temporary ground wire from battery negative to the truck body and see if there is any difference. I've seen this type of problem on older vehicles where the factory grounds looked good but were no longer doing the job. Won't cost you anything to try.

Jordan Walter Enthusiast

Jordan Walter

Posted
  • Author
Posted

Well after driving the truck for a couple days, the voltage seems to start out high - 14.8 to 15.2 volts, and then slowly drop after about 25 minutes down to 12.8 and hovers between 12.8 - 13.1v. If I turn on the head lights it slowly climbs back up to normal 14.3-14.5v. I read in the manual about the RVC (Regulated Voltage Control) and I'm wondering if it's just part of that?

EightTrackHits Enthusiast

EightTrackHits

Posted
Posted

Yes, the changing voltage levels that you are describing is normal, but the discernible flickering or pulsing of interior lights isn’t.  Is that still happening?

EightTrackHits Enthusiast

EightTrackHits

Posted
Posted

A good description of the charging system can be found in this post from an Avalanche club.

 

https://www.chevyavalanchefanclub.com/cafcna/index.php?threads/lights-flicker.52489/

 

Another thing that could cause the flickering is the battery.  Just because a battery is charged to 14vdc doesn’t necessarily mean that it can keep providing current under load if it is unhealthy.  Of course this could also just be some random electrical component someplace in your truck.

 

My 05 has the works, heated seats, electric fans, nice radio, and I haven’t noticed any flickering.  If you’re issue was not intermittent, and you were closer- we could just swap batteries for a bit.  If that didn’t work, you could start pulling fuses to non-essential circuits until you noticed the flickering diminish.  There is the off chance that it is in one of the control modules.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Grumpy Bear
      Slate Electric Truck

      By Grumpy Bear · Posted

      I have thought an EV might have some practical value in extending the life of the ICE members of ones fleet. Now....I'm convinced of it. I've been letting my better half access Raven (Mitsubishi Mirage) for her needs while Dizzy has been in the shop. Being the fuel freak I am and given the fact Raven is capable of over 60 mpg in clean air on a warm day I was taken back by the wife's ability to take a car that had used a half a tank of gas that to that point had returned a value of 57 mpg and return in with a decimating 51 mpg for that same tank in that same day in a 15 mile round trip of short hop errands and a stop in the drive through at Micky D's.  😱   Trust me on this. It would take the remainder of that tank driven on the highway to return that tank to just 54 mpg. This is not a Mitsubishi issue. This is an ICE issue that is magnified in vehicles capable of such high fuel economy values. On a percentage basis your 1500 does the same thing. Short hopping an ICE consumes a good deal more fuel and in doing so provides zero additional useable outputs. That entire volume of fuel is wasted in diluting the cylinder walls oil films, creating crankcase moisture and acid content and the resultant wear.    Enter the SLATE. All of that is avoided and the ICE's advantage in range and made useful at reduced wear for your ICE!   Kind'a cool. 
    • KARNUT
      Slate Electric Truck

      By KARNUT · Posted

      Back in the day people would buy cars based on performance. The charger posted does 0-60 in 3.3 seconds. And it’s fully loaded.  It has a decent warranty and will fit most anyone’s needs. Remember the original Hemi? 90 day warranty. 25K mini truck or that car? I’d go with the car. It wouldn’t fit my perimeter. If I could just talk my wife out of her Genesis. It would be perfect for her.
    • Atlas
      Slate Electric Truck

      By Atlas · Posted

      Let's pivot this back. Someone said they wanted pictures.   Even better, there's already video. Pre-prod prototypes are already on the road and they're letting the press drive them.   JerryRigEverything did a good review. I really enjoy his content and EV adventures, so I was thrilled when he had the chance to review a Slate:    
    • Grumpy Bear
      Slate Electric Truck

      By Grumpy Bear · Posted

      Interesting pivot.  
    • Atlas
      Slate Electric Truck

      By Atlas · Posted

      The Charger EV was stillborn. Wrong car at the wrong price for Dodge's intended audience. Now at a good price with fire-sale discounts, and still not selling, it's still very much the wrong car. Again, Dodge's intended audience. I believe a lot of Stellantis' EV blunders were all under Tavares' regime at Stellantis...the board convinced him to move on. Neat car, just wasn't received on the level that would sustain mass production.   Dodge is headed in a better direction for its core business. I didn't think there was anything left to get excited about re: the Durango after its 15 year run, but they're just now releasing a 392 version that should price out in the low 40's. Nicely done. I'm not sure I would touch anything Stellantis makes with a 10' pole these days, but the Durango is still mostly parts designed like 3 parent companies ago so maybe it's still OK?

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...