2017 Losing Battery Connection

DeePa · December 19, 2021

Hey all,

2017 Sierra 5.3. Replaced battery a month ago. The other night after a 50 mile drive, I was unloading the back seat and the interior lights went out. Went to try to start the truck, and nothing at all. No dash, no interior lights, no crank.

I went under the hood and wiggled neg and pos cables and then power returned and truck started.

fast forward to today (2 days later). Same thing happened. Took off the battery cover hoping to find a loose terminal, but both were right. All connections on that power distribution block were tight also. I wiggled the junction block and then the power returned and truck started.

Has anyone had anything similar happen? My next step is to take off all terminals and clean / dielectric grease them.

im also considering buying a new distribution block and swapping it out, but I haven’t been able to find the correct one yet.

thank you

Mike

M1ck3y · December 20, 2021

It could be from corrosion. Sounds like you're taking the right steps :thumbs:

Edited December 20, 2021 by M1ck3y

BlaineBug · December 20, 2021

Check the ground wire beneath the wheel liner, behind the passenger side front wheel. Remove the bolt from the frame and clean the contact area. Secondly, check the HOT wire connection that connects from the battery to the main fuse/relay box under the hood above the driver side front wheel well.

DeePa · December 22, 2021

Will do.

does anyone else have any suggestions?

I’ve read a lot about bad starters but with a 17 and 124k I think it would have failed by now if it was junk from the factory.

dieselfan1 · December 23, 2021

You could also check the ground straps under the cab.

On my 18 the battery failed at around 40,000 miles and the starter failed around 50,000 miles.

Supreme Pizza · December 23, 2021

For battery connections, you really want to use the proper cleaning tool, and be aggressive with it. The post and the clamp should be 100% clean. I always loosen the clamp more than needed, and then what I do is place the terminal on the post, and put a socket on top that only touches the clamp and not the post. Then I tap the socket, to drive the clamp all the way down the to the bottom of the post. This will spread the clamp open further, allowing the clamp bolt to be tightened more easily and more effectively. Once the clamp bolt is tight, I try to twist the clamp on the battery post. I really give it all I got to try to turn it. If I'm able to turn the clamp at all - then its not a good connection and needs to be reworked again. You should never be able to move the clamp at all by hand. When i was in auto shop, the teacher used to put a strip of paper around the battery terminal, and then install the clamp. Then the newer students would have to figure out why the car would not start.

Here is the cleaning tool for under $4.

https://www.amazon.com/Schumacher-BAF-BI-Terminal-Cleaning-Brush/dp/B0060YHP62/ref=sr_1_3?keywords=battery+post+cleaner&qid=1640221718&sprefix=battery+post+%2Caps%2C416&sr=8-3

DeePa · January 4, 2022

I finally got around to checking out where the negative cable grounds.

I pulled the passenger front fender liner this afternoon. The ground in the block was clean but I took it apart and sanded it up / greased it up anyways.

the ground behind the passenger tire had 1/3 of the plastic terminal insulation between the frame and the terminal. Also, there was a good bit of wax and some rust there too. So I cleaned it all up and hopefully that fixes my problem. I’ll drive it for a bit and let you know if anything changes.

I still plan on swapping the negative cable at some point, hopefully during the warmer months.

I’ll chime back in if the truck starts acting up.

im trying to rule out one cable at a time so there’s some clarity for others that are going through this. There are a lot of posts about these trucks doing stupid ****** once they get to be a few years old.

BlaineBug · January 4, 2022

1 hour ago, DeePa said:

I finally got around to checking out where the negative cable grounds.

I pulled the passenger front fender liner this afternoon. The ground in the block was clean but I took it apart and sanded it up / greased it up anyways.

the ground behind the passenger tire had 1/3 of the plastic terminal insulation between the frame and the terminal. Also, there was a good bit of wax and some rust there too. So I cleaned it all up and hopefully that fixes my problem. I’ll drive it for a bit and let you know if anything changes.

I still plan on swapping the negative cable at some point, hopefully during the warmer months.

I’ll chime back in if the truck starts acting up.

im trying to rule out one cable at a time so there’s some clarity for others that are going through this. There are a lot of posts about these trucks doing stupid ****** once they get to be a few years old.

Got to love that, that's similar to what the G218 ground issue was pinching insulation between grounding plane and the wire eyelet. If QC missed things like this during the good years I can't imagine how bad QC is today.

Edited January 4, 2022 by BlaineBug

mikeyk101 · January 5, 2022

Ooops, I saw you already know about this because of your post in other thread.

Edited January 5, 2022 by mikeyk101

DeePa · January 25, 2022

No issues after cleaning the ground. I never even swapped out the negative cable.

BlaineBug · January 25, 2022

2 minutes ago, DeePa said:

No issues after cleaning the ground. I never even swapped out the negative cable.

I think you're exactly 3 weeks since you posted about this "fix." Do you believe the issue would have shown itself by now? Sometimes waiting for an issue to resurface (or not!) can make you feel huge mistrust and a lack of confidence in your vehicle, I know!

DeePa · January 25, 2022

Yeah. It was getting more and more frequent before I finally got my hands dirty with it.

BlaineBug · January 25, 2022

My symptoms never seemed like a power outage but involved U code for loss of communication with ECU. They found this ground in a similar state such as yours and they replaced the ECU as well so, I'll never know which was my issue. I ended up removing the ground myself and cleaning it up further and then painted it once it was re-installed in place for a hopefully long term fix.