2020 3500 Parked ~ 48 hours - Dead battery no apparent reason. FYI and any thoughts?

[schiker]

FYI will update as I know more....... Chime in if you have any similar experiences.

Unexpected dead batteries for no apparent reason.

Still New truck IMO ~ 3 months old ~ approx 150 hrs 4,900 miles 2020 3500 HD CCLB SRW LT AllStar PKg. Convenience Pkg II BUT most options turned off as far as I know. Think all I have used is Satelite radio (combo account with wife's car).

I went to crank it after it had sat for about 48 hours and it was dead: nothing my doors were unlocked but wouldn't operate the locks dead dash and media screen etc.

I put a battery charger on it at 50 amps for about 15 min, removed, and it started slowly and the dash volt gauge was low 12-13 volts once running. A little RPM and it reads 14 V; the fan on and or blinker and the guage dipped. Drove it and it came up to 14V. Sat overnight cranked like regular and read very close if not14V after guage sweep. Runs normal no other indications of problems.

I had opened doors and got some stuff out the day before but everything was off as far as I know.

A friend works for a Municipality with a small fleet of GM WT's and says some of their newer GM trucks occasionally require a jump after sitting 3/4 days plus ??????? Their dealer is not too helpful as they have fleet accessories added lights etc.

I called my nearest dealer as I thought it might be a dead cell battery and wanted a warranty claim. They say they are swamped and can't see me til Monday but I can't make it then. Says they have to do a full procedural test that could last up to 2.5 hrs to prove batteries are bad before replacing under warranty.

 

[WarWagon]

You can check your own batteries quick enough. How long did it sit on the dealer lot with dead batteries before you purchased it? : typical reason for early battery failure on new vehicles.

OnSuck, esp. when not activated, has been known to suck batteries dry in a week since it came on the market. Typically the OnStar fuse gets pulled by the owner and in many cases is a separate inline fuse off the battery positive terminal. Did I mention it quickly sucked the batteries dry on the dealer lot?!

Otherwise sometimes a module won't "go to sleep" and drains the battery. Air ride is famous for this.

 

[FellowTraveler]

You sure the GPS and or anti theft devices are not broadcasting for no apparent reason..........I have heard of this problem when such devices are installed.

 

[schiker]

I do have to learn what goes on in the background.
I had previously gone through the media screen and looked through all the settings I could scroll through and most were off that did not seem functional wifi, data sharing, etc. I don't like On Star and don't have any billed plan but that is not to say it is not doing something in the background. I'll have to look into pulling that fuse. I don't have a mobile data plan either and have settings off I believe. I do have to cut my phone's wifi off because it tries to connect to the truck and safari just hunts because there is no plan. I will forget the network on my phone.

I guess nowadays sitting on the lot is relative due to electronic load. I am sure other trucks sit much longer this being a CCLB not all loaded up they were hard to find and turned over quickly when priced accordingly. I found it on the internet basically and drove out of state to get it from a big high volume dealer who said they ordered it.

 

[WarWagon]

I have used OnStar in the past as it has better range than a standard cell phone in some areas we delivered parts to in AZ. Other than that it has few, if any, other useful benefits for it's cost. One family member's vehicle eats batteries by overdischarge from sitting and they have not been able to find the OnStar fuse... Of course the dealer won't pull it either for safety.

 

[FellowTraveler]

I have seen reports that some dealer installed trackers HOG lots of power "the installs" are the result of staggering amount of people defaulting on their vehicle payments......these days.

 

[Rockabillyrat]

Perform a parasitic draw test. It can take up to an hour for computers to go into "sleep mode" so you need to wait at least that long without touching anything to confirm the size of the draw. I like to leave the drivers door open and manually close the latch with a screwdriver so it thinks the door is close. That way you can a access the interior fuel panel without opening the door causing the computers to "wake up"

If you are pulling more that .050amps then you have an excessive draw on the battery. Although newer vehicles may have slightly more allowances because of the large number of electronics. To find what circuit had the draw voltage drop your fuses in millivolts. If you see anything on the meter over 0mv pull that fuse and see if the draw goes into spec.

 

[MrMarty51]

I have used OnStar in the past as it has better range than a standard cell phone in some areas we delivered parts to in AZ. Other than that it has few, if any, other useful benefits for it's cost. One family member's vehicle eats batteries by overdischarge from sitting and they have not been able to find the OnStar fuse... Of course the dealer won't pull it either for safety.

Wifeys 08 Mailblu discharges the battery, but, it sets for months and months at a time, I got a battery maintainer kind of a thing and hooked to it. Got tired of when We needed the car the battery was always dead.

48 hours is a pretty short span for a battery to be drawn down that much. My K3500 has all LED bulbs for interior lamps, I once screwed up and left on the dome lamp, a week later went out and the battery was low, it cranked but I could tell it was going to need some help, charger on 40 amps for an hour and it fired right up.
I am sure that Your new truck must have LED bulbs come factory, so, doubtful that an interior lamp would draw it down that fast.

 

[schiker]

My truck was parked for a week without use and cranked up fine. Guage read normal 14V after sweep even with the ac fan on low.

So I guess I'll wait and see if anything presents further.

 

[tborba2]

2020 - 2500 GMC Sierra HD, less than 7000 miles. Go out to start the truck and dead, no lights no clicking, no anything. Called the dealer and they stated I would have to have the truck towed to the dealer to take advantage of any warranty issues. Problem is, due to a new vehicle, I did not carry towing insurance. Who does? Learned my lesson there. $110 tow. Tow driver stated he personally has towed numerous new GMC pickups for the same issue. He suggested I plug a trickle charger in when I park the truck. Not convenient at all.
I will add when or if I hear any confirmed issues.

 

[Will L.]

Fight them over cost of having towed unless they show it was your fault like interior light left on.
Following around potential customers to buy new truck and telling them directly not to buy is against law in some places. But sitting in showroom talking loud on your cell phone explaining the cost because of this frequent issue in brand new trucks while they are trying to close deals might bring a result. A $110 loss one time offsets the loss of one sell pretty quickly. Having someone you know stage the loss of a sale has been done before also and brings results too...

Dealerships can pin more to the factory than is let on...

 

[NVW]

I have used OnStar in the past as it has better range than a standard cell phone in some areas we delivered parts to in AZ. Other than that it has few, if any, other useful benefits for it's cost. One family member's vehicle eats batteries by overdischarge from sitting and they have not been able to find the OnStar fuse... Of course the dealer won't pull it either for safety.

On our 2004 Yukon Denali the On Star fuse is in the engine fuse block. Ours will be good for months on end then go dead over night. Once my wife went for coffee and in 1 hr it was dead.

I bought a clamp on ammeter and found the radio and sig lighter would draw high amps when it was acting up. With those fuses removed it's been much better. The radio amp was nfg anyway, likely the problem.

 

[schiker]

My truck has been fine hasn't happened again. But no real test it hasn't sat for more than 3 days since.

I have read of few other trucks going dead on one of the facebook groups. Reports are randomly posted mostly once and done. A few dealers give new batteries others don't. Some tow to a dealer some jump off and go.

I haven't read or heard of any found problem when taken to a dealer.