Jump to content

Chmsl 3rd break light fuse keeps blowing.

DvdFish

By DvdFish
in Troubleshooting & Recalls

 Share

Recommended Posts

DvdFish New Member

DvdFish

Posted
Posted

Hey guys just wondering if anyone has experienced this problem as I can't find anything on it. 

 

Recently noticed my 3rd break light not working and found the fuse blown. Fuse #38 I believe a 10a fuse in the box under the hood on my 2014 High Country 1500 5.3.

 

Well I replaced the fuse and as soon as depressing the break the fuse blows again. I kept replacing fuses working up in amperage until I got one that would work without blowing, a 30a.

 

I'm not comfortable with it in there, is there a chance of overheating wires or any possible electrical problems if I leave the 30a in place?

 

I've tried regularly 921 bulbs in the 3rd break light and took the chance on a Sylvania led 921 hoping it might help but no avail. 

 

Any idea what might be happening?

Thanks

64BAwagon Senior Enthusiast

64BAwagon

Posted
Posted

You have a short somewhere in the circuit, replacing the fuse with a bigger one will ultimately destroy the wire from the power source all the way to the lamp and may cause a fire.  You will need to have the circuit diagnosed and please remove that 30a fuse until you can get it repaired. 

diyer2 Senior Enthusiast

diyer2

Posted
Posted

WOW

Not the smartest move. Circuit is designed for a 10 amp fuse.

DvdFish New Member

DvdFish

Posted
  • Author
Posted

 

6 hours ago, It's Tim said:

Is the bulb socket corroded?

Tim no the socket isn't corroded and it doesn't appear to have any of the typical moisture problems these trucks have been known to have.

7 hours ago, 64BAwagon said:

You have a short somewhere in the circuit, replacing the fuse with a bigger one will ultimately destroy the wire from the power source all the way to the lamp and may cause a fire.  You will need to have the circuit diagnosed and please remove that 30a fuse until you can get it repaired.

The fuse isn't in there I wasn't comfortable with it. Posted here for y'alls opinions and thank you for guys for the replies. Any idea what might be causing this or where in the circuit there could be a short? 

 

The truck it bone stock besides led reverse and license plate lamps.

64BAwagon Senior Enthusiast

64BAwagon

Posted
Posted

Try to find the route that wire takes to the back. I have seen a number of trucks with wiring issues due to corrosion and chafing under the sill plate on the door, especially if the door gasket isnt in good shape. I would check the socket very carefully also, I have chased a few shorts when the socket looked okay but was ultimately the problem. Lots of places for a wire to get rubbed through. 

  • 4 months later...
DvdFish New Member

DvdFish

Posted
  • Author
Posted

Months later finally I have a response and what the problem was, thank you guys.

 

Failed inspection today...I had completely forgot about all of this. I had given up after I couldn't find anything as well as a couple of the local mechanics.

 

Anywho, failed inspection and went looking again. Found a bundle of wires above the spare tire coming off where the trailer connections are. They were sip tied up to the drivers side break light and cut/bare ended. One of the wires had worn through and was bare wire on the frame.

My only guess is that whoever owned the truck before me had installed a camper shell. I cut it all out and heat shrinked anything I found open. Wish I'd have taken before photos.

20230406_221540.jpg

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,760
    Total Members
    8,960
    Most Online
    MASONV88888888
    Newest Member
    MASONV88888888
    Joined

  • Who's Online   3 Members, 0 Anonymous, 1,609 Guests (See full list)

  • Latest Articles

  • Posts

    • Coastie05
      Replacing 2.7L on 2021 Silverado with 2023 2.7L

      By Coastie05 · Posted

      I’m definitely interested to hear the end result here. 
    • MASONV88888888
      Another 6.2L engine failure!

      By MASONV88888888 · Posted

      My 2025 Silverado 1500 had to receive a brand-new engine (long block) under warranty last month at only around 16,500 miles. Before the replacement, the truck repeatedly displayed "Engine Oil Level Low" warnings, even though the Oil Life Monitor still showed around 50% remaining after about 6,000 miles since my last oil change. After seeing the warning several times, I checked the dipstick with the engine cold, and the oil level was completely normal. The next day, the message escalated to "Add Engine Oil." At first, I assumed it was just a faulty oil level sensor, so I brought the truck to the dealership. After inspecting the engine, they found internal cylinder wall scoring and ultimately replaced the entire long block under warranty. Before this happened, I was planning to install a 4-inch lift and suspension upgrade on my truck. After needing a new engine at just 16,500 miles, I honestly don't see the point anymore. I also contacted GM to ask whether my vehicle qualified for a buyback, but I was informed that it does not at this time. Anyway, this experience has left me with serious concerns about the long-term reliability of this engine. I sincerely hope NHTSA expands the current investigation or recall to include 2025 model and performs a thorough inspection of affected vehicles. My biggest concern is that these engines may fail shortly after the powertrain warranty expires. If GM truly stands behind this engine, then at the very least, please consider extending the powertrain warranty to 10 years for affected owners. That would go a long way toward restoring customer confidence.
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      Without exception but then I'm the odd duck, right? I know what goes into that test, how it is calculated and thus how to beat it. But EPA values are often not beaten by the general public and the government has in past years adjusted the means and methods to come to those values to more closely approximate "Joe Average".    The only real trick to beating that EPA average is don't drive like "Joe Average".    It's the same method you used to profit from "Economic Migration" and in doing so beat the 'stats'. But you, like me, are not "Joe Average".     The thing you don't seem to grasp is this "Purchasing Power Index" isn't forward looking. It doesn't predict what it going to be but looks backward and states what it was. They are not telling us what the THINK, they are telling us what they MEASURED. Example:    Wife says "I'm going to lose 40 pounds by Christmas". May she does, maybe she doesn't but the doctors office who weighed her when she made that statement and again at Christmas only REPORTS what the RESULT was. You and I can banter about what was possible and what aunt Tilly did till the cows come home but the result is the result. Arguing otherwise is.....irrational. That's all I'm saying. This isn't about:      What you are calling a 'Statistic' is a RESULT not a CALCUATION and as a result the RULE. Like gravity as a rule, it can not be broken. 
    • MASONV88888888
      Rattle in the rear!

      By MASONV88888888 · Posted

      Just wanted to say thank you for posting this. Years later, your thread is still helping Silverado owners.   I bought my 2025 Silverado 1500 in January 2025, and I've had what feels like the exact same rattle since day one. After reading your findings, I believe my truck has the same issue with the cable carrier contacting the rear sliding window. To be honest, I had pretty much given up on pursuing the issue. It wasn't until I recently drove another brand's pickup that I realized just how quiet their cabin was—and how noisy mine has been all along. On my truck, the rattle happens on almost any paved road, gets even worse on rougher pavement, and I can even hear it during braking and acceleration.   I actually referenced your thread when submitting my case to GM, hoping they'll recognize this as a recurring issue instead of treating it as an isolated incident. The reason I reached out to GM first is because my dealership told me they would need to keep the truck for at least two days just to diagnose the problem. I was concerned that even after two days, they still might not be able to identify the source of the rattle before giving the truck back to me. I had also asked a few dealerships about this issue during previous service visits, but none of them seemed to know what was causing it or had a solution. That's why I decided to contact GM directly first, hoping they might already have an official repair procedure or guidance for this issue.   I also hope GM eventually comes up with an official fix for this problem. I have a feeling there are many Silverado owners experiencing the same rattle, but most either choose to live with it or simply don't know what the cause is.   Really appreciate you taking the time to document your diagnosis. Your post is still making a difference years later.
    • Buckwild27
      Gas Prices

      By Buckwild27 · Posted

      I have 2 choices. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...