[SOLVED] Battery or Alternator or Starter?

[intergalactron]

My 2020 Tahoe (5.3L, 130K miles) has a starting problem. It almost always starts, but cranks slow. Maybe 1 time out of 20 when I bump the key it won't crank. Its been doing this for months now. Battery is about 3 years old. Volt gauge is always around 14-15 when running. Starter and alternator are originals. Temp doesn't seem to matter (engine temp or environmental temp). I did try charging my battery once and I did get stronger cranking for a couple of days, but it didn't last. I have gotten a low voltage warning on the info screen a couple of times, but not by any means consistently.

What do you think? Battery, Alternator, or Starter? And why do you think what you think?

 

[intergalactron]

I should add that when I get a no crank, I'll try it again immediately and it will almost always crank. Just slow.

 

[Tonyv__]

In my experience on this generation, Starter.

Idk if it’s these newer trucks or what, I’ve always had a starter just die, not crank slow

My 2015 Yukon is the first vehicle I’ve experienced a slow starter.

 

[Tonyv__]

Hard to hear with the alarm but does it crank like this?

 

[Doubeleive]

I would probably lean towards the starter as well, but you should not be getting low voltage
I would get under it and inspect the starter cable, on the k2's they are prone to getting burnt due to insufficient insulation at the starter connector.
if the cable covered in carbon/looks burnt then if you replace the starter get a new cable also.

 

[intergalactron]

Hard to hear with the alarm but does it crank like this?

Sort of... That darn alarm...

 

[intergalactron]

I would probably lean towards the starter as well, but you should not be getting low voltage
I would get under it and inspect the starter cable, on the k2's they are prone to getting burnt due to insufficient insulation at the starter connector.
if the cable covered in carbon/looks burnt then if you replace the starter get a new cable also.

What I find odd about it is that it doesn't really seem to be getting any worse. I suppose checking cables and terminals and etc. isn't a bad place to start.

 

[Miami-Dade]

My 2016 had very slow starts for months. It was the starter.

 

[Doubeleive]

What I find odd about it is that it doesn't really seem to be getting any worse. I suppose checking cables and terminals and etc. isn't a bad place to start.

the starter motor could be basically toast but still working, it happens

 

[Fless]

Pull that battery out and give it a full charge. Have it tested with a good load tester by a qualified shop.

You could also do a complete voltage drop test to determine if a heavy current-carrying wire or connection is compromised.

At the same time you can determine if the alternator is putting out enough amps, as well as if the charge is making it to the battery, which is a function of the quality of the main cables and grounds.

Most of this is testing; no parts required unless something is showing as defective.

 

[Tonyv__]

Sort of... That darn alarm...

i forget why my alarm would go off on remote starts but we fixed that.

 

[Joseph Garcia]

What I find odd about it is that it doesn't really seem to be getting any worse. I suppose checking cables and terminals and etc. isn't a bad place to start.

You've asked for advice, and we are giving it to you.

Start with the easy stuff, like checking your battery cables and terminal connections to make sure that they are clean and tight. Same with the ground strap that that connects the motor to the firewall. Same with the cable connections to the starter. Put an Ohm meter on the battery cables to make sure that the wire's resistance is close to zero Ohms, and not compromised through internal corrosion. That will ensure that the pathways for the electricity to flow when starting the truck are in good shape.

After completing the above, if you still have this issue, take the battery out of the truck and take it to an auto parts store with a bench battery load tester, as this is the only true way to test the condition of your battery.

If the battery condition is still good, then look at replacing the starter.

 

[intergalactron]

No need to get snippy. Was just a comment.

 

[fozzi58]

Do as the others above have said. I would agree with them thats its most likely the starter. I had electrical issues in my 17 and it turned out to be faulty ground cables. It would affect my starting, but it would affect other stuff as well. I would probably make that step 2 after doing a full battery charge out of the truck. Just my 2¢.

....My 2015 Yukon is the first vehicle I’ve experienced a slow starter....

I guess you never owned a mid-70's F-Body. Sometimes a hammer would fix those slow start/no start conditions.

 

[Tonyv__]

I guess you never owned a mid-70's F-Body. Sometimes a hammer would fix those slow start/no start conditions.

lol I actually do know the hammer trick. But again, never a slow starter, it usually just doesn’t crank at all. Tap it with a hammer and it cranks.

 

[Cranker57]

My 2020 Tahoe (5.3L, 130K miles) has a starting problem. It almost always starts, but cranks slow. Maybe 1 time out of 20 when I bump the key it won't crank. Its been doing this for months now. Battery is about 3 years old. Volt gauge is always around 14-15 when running. Starter and alternator are originals. Temp doesn't seem to matter (engine temp or environmental temp). I did try charging my battery once and I did get stronger cranking for a couple of days, but it didn't last. I have gotten a low voltage warning on the info screen a couple of times, but not by any means consistently.

What do you think? Battery, Alternator, or Starter? And why do you think what you think?

I just had the same problem. I took it to Auto Zone and they checked my battery and alternator, they said they were fine, but my Starter was bad. I replaced the starter and every thing is fine.

 

[Doubeleive]

I have only really heard of the slow starter issue since the K2's came around, previous to this it was dead or alive, a hammer smack would usually resuscitate for getting home or to work. ditto for the fuel pump. Otherwise if you hear click/click/click= dead battery

 

[intergalactron]

Well, got a warmer day yesterday so I had a deeper look at this. After inspecting connections, I got a new starter. Problem solved.

I still think it's odd that it wasn't getting any worse.

 

[346wizard]

If you have time on a weekend, it's likely still worth the effort to pull all of the grounds and power leads to clean up the connectors and studs. Use some dielectric grease or Fluid Film to keep the gremlins away in the future.