2018 Chevy Silverado 1500 LT Crew Cab - Intermittent Start Issue

Jan Scott · December 25, 2021

Symptoms: (1) Driver’s side window sometimes (infrequent) will not stop going up and down when I want it to just go up or just go down--until you hold the up button position for several seconds--then it's ok; (2) Mystery pinging/chimes while driving with no warning light illuminated on dash (infrequent—no consistent conditions and no known cause or issue) (3) Intermittent starting issues. Tapping on the battery junction box and jiggling battery wires seems to solve the problem so truck starts. Intermittent starting issues don’t appear to be related to driving weather, humidity, ambient temps where truck is stored, or number of miles driven. When truck finally starts, system resets as if a new battery was just installed (e.g., clock changes time).

Status: New battery was just installed by dealership when I took truck in for routine oil change. Mechanic said battery was dead and truck wouldn’t start (yeah—probably the same intermittent starting problem I had been experiencing but forgot to tell them about--I also neglected to ask them if they actually checked the battery cells to see if the battery was indeed "dead"). Old battery had not been giving me issues relative to being “dead” although I did have a few start issues, so I never thought there was a battery problem. So the battery does not seem to be the root cause since the start issues are still happening even with a new one installed. I’m afraid the dealership will ream me for checking everything and insisting that I buy 5 new parts in the hopes that one of them will “fix” the issue. As a female, I'm already at a disadvantage for being lied to (it's happened in the past).

Things to Check?: Starter? Starter solenoid? Wires to the starter? Water infiltrating negative battery cable and rotting it out? Replace both the positive and negative side battery cables? I checked the fuses including relay and all appeared to be ok. Would a bad junction box be something to check? Worried to even drive the truck at this point for fear it won't start even with my tinkering with it in a parking lot. Found these things to check on another blog--maybe get these things checked? Blown 57 or 62 fuse in underhood fuse box; damaged wires or bad ground connections to various switches (e.g., P/N switch; IMS; TCM); bad switches...

If I go to an auto repair place, can I ask them to check specific things or do I have to be at their mercy for checking everything and them guessing but telling me something has to be replaced--based on their guess?

DeePa · December 25, 2021

I’m going through the same thing with my 17. If I move around the junction box on top of the battery, it’ll start. It’s been fine for a week now that I zip tied the junction box so it stays still. It doesn’t clip down as well as it did to the OEM battery.

theres a post I started a few lines down with some info. I haven’t been able to check on any of the suggestions yet.

my truck has high miles (124k) so I may just change out the junction box, positive cable, and negative cable.

when my truck won’t start, I do not have any power at all. No dash, no interior lights, etc.

Supreme Pizza · December 25, 2021

Well, to start with, I would say that the shops screw everyone equally. I don't think that you being a female really makes much of a difference on the bill.

It sounds like a bad connection somewhere.

Automotive electrical diagnostic shops are pretty expensive, but they might have better luck tracking down the problem as opposed to a standard car repair shop.

One thing you could try, would be to beat the hell out of the suspension, by going over train tracks, or a really rough road.

If its a loose connection, that would either fix it, or it would break it. Either option would be better than what it is now.

An unreliable vehicle is about as useful as one that doesn't run at all.

Intermittent problems are always the hardest to diagnose.

Once its not working at all, then its easier to find the problem.

Might want to get premium AAA road side assistance before doing the test.

Your insurance may offer free towing as well.

Edited December 25, 2021 by Supreme Pizza

Jan Scott · December 26, 2021

@ DeePa - Thank you--so I don't feel like I'm losing my marbles because the junction box seems to be the peanut that allows me to start my truck!

@ SupremePizza - Thanks for the suspension test suggestions and the photos. It made me laugh to see the photos you sent. I'm also slightly comforted to hear your opinion that everyone is screwed equally at dealerships--I still feel like an easier mark, unfortunately.

"Duh" on my part for not including in my original post.: As others have mentioned in their similar stories: the dash, lights and radio all come on as normal until the key is turned to the start position. I turn the key to the 2nd position and then everything goes off/black. Taking out the key and trying again--no dice. As I mentioned in the original post, I open the hood, tap on the junction box of the battery and jiggle some of the wires near the battery. Voila--the truck then starts. No readily apparent rhyme or reason for the truck to suddenly start, but likely not a good approach for ensuring that the truck will start 100% of the time....

Based on numerous earlier posts on this website about the "fix" being replacing the starter with associated positive and negative battery cables replaced as well, I'm really tempted to go that route.

DeePa · December 30, 2021

So my truck acted up again.

I tried moving around the junction box on the top of the battery and there was not any change.

I then moved the negative battery cable around and then power came back and the truck started.

I ordered a new negative cable and plan on inspecting where it connects on the frame before I replace it completely.

price was around $50 shipped to my door.

I’ll post back with how it worked once I get a chance to install it / fix the current one.

Edited December 30, 2021 by DeePa

mikeyk101 · December 30, 2021

3 hours ago, DeePa said:

So my truck acted up again.

I tried moving around the junction box on the top of the battery and there was not any change.

I then moved the negative battery cable around and then power came back and the truck started.

I ordered a new negative cable and plan on inspecting where it connects on the frame before I replace it completely.

price was around $50 shipped to my door.

I’ll post back with how it worked once I get a chance to install it / fix the current one.

After getting your new negative cable, you may want to ziptie it as described in this thread. Start reading towards middle of 2nd page with @Dick Lichon post and keep going through the thread to see the example of ziptieing the negative cable...

There is a design issue on these vehicles with the amount of stress the negative battery cable places on the post. I got 4 years out of the original and replaced with a AGM just over 1 year ago. Again same negative battery post failure. The bending moment on the post induced by the negative cable fatigue cracks the post inside the battery. The plastic housing holds everything together and you will pull your hair out when temps and moisture cause the air gap in the cracked post to create resistance build up losing voltage and amp draw. Both times mine exhibited starting issues given the amount of amps you need to turn the motor over. Easy way to tell if your post has failed internally is to put a 10mm socket and wrench on the nut of the negative cable and tighten the nut only placing a small amount of torque on the post while someone is trying to start the engine. The post will generally fail on the right side and propagate toward the driver side given the bending moment of the unsupported cable length. There is a hole in the trough above the cable that I used to use a zip tie to support the cable and reduce the stress on the post. You guys may want to do that first chance you get. Hope this helps those experiencing electrical issues that tend to come and go until it finally cracks far enough to put you dead in the water. Regards!

https://www.gm-trucks.com/forums/topic/243257-battery-replacement/?do=findComment&comment=2463664

DeePa · January 4, 2022

They changed the negative cable and it’s routing on the later k2 trucks so mine does not have that constant tension on the battery terminal.

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.