2014 dead battery out of nowhere

cbrsilv15 · August 9, 2018

I have never had any issue with charging ever with my truck. Drove home last night with the air on and parked it in the garage as usual. Nothing left on. I went out first thing and it was completely dead. It would only click once when trying to turn over. I had my wife put the battery tender on it since I took the bike to work instead. Came home and it started right up, so I took it to Autozone to have th electrical system checked. Battery was put under a load and tested okay, but needs charged as it was only at 69% capacity. Tested the alternator and the capacitors passed, but the voltage regulator failed. I was told the alternator was bad, so I just drove it home since a new one is $270 there. I used my voltmeter and it rear 12.3 off and then jumped to 13 when running. Revved up a little and it was at 14. Completely normal. Very weird. The only thing I did differently was that I left the AC on the entire way home and turned off the truck while it was at full blast. Maybe something electrical stuck open and kept everything energized? I don't know. I will check in the am and see how my voltage is. I'm hoping it was just a fluke, but I've read a lot of threads about bad batteries, so I typed this one in case it ever happens to someone too. I'll report back tomorrow.

da90 · August 9, 2018

My 2014 Sierra just had a bad battery. I believe it was the original so it was about time. Mine went dead one day then entire next day was fine. Went to go to work Monday it wouldn’t start at home or after I got to work.

Check out what my buddy sent me. He works at a local dealer.

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cbrsilv15 · August 9, 2018

It's weird that it tested okay, just low, and the alternator voltage regulator failed, but the capacitor passed..

Hoping it'll be the battery and not the alternator. Time will tell. I got 10 yrs on my old truck with the OEM Delco battery. Tons of aftermarket stuff added too.

Spendit · August 9, 2018

Same thing almost - Batt was just dead next day after towing boat home. Put it on the charger overnight - fired right up and off to work - come out 10 hours later and measure without running, 12.34V - start it up and measure 13.8V - starts up fine next morning - dead at work after sitting. Did not waste time, new batt in place and monitoring for draw or charging issue. 2014 original batt, I am 2nd owner so who knows how many cycles the other guy put the batt thru.

cbrsilv15 · August 9, 2018

It was at 12.2 this morning. Started it up and drove it to work. Fired right up when I went to leave. Was charging at 14v constantly the whole drive, so it all seems normal. Checked voltage when I got home and it was back to 13.2 once I turned it off at around 4pm. Back to 12.88 after sitting for 3 hrs. I'll report some more as time goes on.

TJay74 · August 10, 2018

I would not trust the stores alternator testing systems on the new GM vehicles that have adaptive battery charging systems on them. The computer turns the charging system in the alternator on/off as needed to charge the battery. When the battery is charged the output turns off to reduce load on the alternator and the parasitic drivetrain losses to help out with fuel economy.

You could have a bad battery that had an internal short, or as said some of the 14's had issues with the battery cables. There was a TSB out for that at one point.

swathdiver · August 10, 2018

16 hours ago, cbrsilv15 said:

It was at 12.2 this morning. Started it up and drove it to work. Fired right up when I went to leave. Was charging at 14v constantly the whole drive, so it all seems normal. Checked voltage when I got home and it was back to 13.2 once I turned it off at around 4pm. Back to 12.88 after sitting for 3 hrs. I'll report some more as time goes on.

Time for a new battery.

Look up EPM and RVC. Electrical Power Management and Regulated Voltage Control

cbrsilv15 · August 11, 2018

That’s kind of what I was thinking. Drove it to work and it charged at 14v. Drove it to my dads and it wouldn’t raise above 12. Battery was at 12.8 when I turned it off. Drove it home after my dads and it was on 14 again. I know about the voltage fluctuation, but it’s never down in the 12’s while running and driving. Always 13-15v.

diyer2 · August 11, 2018

IMO

Batteries of today won't last like the old days.

4-5 years is average IMO.

A new battery is what I would do.

Justin101714 · August 11, 2018

Also don’t forget the 2014-2015 models years were plagued with bad battery cables. I would replace the negative cable, both positive cables or you could very well be repeating the battery replacement sooner than you’d like.

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cbrsilv15 · August 11, 2018

Oem cables the way to go Justin? Any link to the TSB? I can’t seem to find it. Also, if it was just a bad cable, why would the battery drain completely? I would think it just wouldn’t start. Load tester on the battery said it was fine.

Justin101714 · August 11, 2018

Oem cables the way to go Justin? Any link to the TSB? I can’t seem to find it. Also, if it was just a bad cable, why would the battery drain completely? I would think it just wouldn’t start. Load tester on the battery said it was fine.

No TSB for the concern. Just have done an ungodly amount of them. Over time, if you have high resistance through the cabling, the battery never receives the proper charge, the cells die slowly and when the cell decides to go, it just goes, so now you’d have a battery which should be at 12 bolts or higher, now sitting at 9 volts or less, it won’t be able to support module wake up.

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cbrsilv15 · August 11, 2018

Have you just replaced the cables and been fine, or did you have to replace the battery at the same time?

Negative cable https://www.amazon.com/ACDelco-22846471-Original-Equipment-Negative/dp/B00PM32Q02

Did you always replace both, or just the negative? Thanks again!

Lgetz · August 11, 2018

If your battery is still the original one change it out. My 2015's battery lasted just a bit more than 2 years before it went. Buddy's 2015 Suburban went out a week before mine. Both use our vehicles sparsely and S Texas heat is murder so that may have contributed to batteries early demise.

eMc9002 · August 12, 2018

On 8/11/2018 at 10:55 AM, cbrsilv15 said:

Have you just replaced the cables and been fine, or did you have to replace the battery at the same time?

Negative cable https://www.amazon.com/ACDelco-22846471-Original-Equipment-Negative/dp/B00PM32Q02

Did you always replace both, or just the negative? Thanks again!

Curious to see how this work's out for you because I'm in the exact same scenario. I ended up replacing the battery and it worked fine at first but the next day after heading home it had an extremely hard crank. I 'failed' the alternator test at the local auto store and was going to order one but I may try the cable's first.