Jump to content

3rd brake light not working

FL335i
 Share

Recommended Posts

FL335i Enthusiast

FL335i

Posted
Posted

Did a LOF and some service to my truck today, figured I'd do a functional light check. The 3rd brake light is dead as a door nail. Truck is only 2 yrs old with 51,300 miles. Before I go ripping it apart, does anyone know if the thing works while parked? I even had the wife put it in Drive, still no brake light. I also need to check the owner's manual for the bulb part #. Always something. Thanks in advance.

  • Like 1
Gary13 Enthusiast

Gary13

Posted
Posted

It will and should work any time the brake pedal is pushed. Sounds like a bulb out. I believe it's a 906 bulb, but check with your local parts store for the correct lamp size. Should be an easy fix while standing in the bed!

  • Like 1
SouthernSilveradoGuy85 Senior Enthusiast

SouthernSilveradoGuy85

Posted
Posted

Manual says the brake light bulb for the 3rd is 921, more specifically 921LL. Just so you know, the manual calls it a Center High Mounted Stoplamp and not 3rd brake light. Just in case you can't find the description of 3rd brake light.

FL335i Enthusiast

FL335i

Posted
  • Author
Posted (edited)

I just checked my OM. 921 #. Turns out I had a brand-new 921 in my stash of bulbs. Leftovers from either my brother's 2000 WS6 F-body or my C4 vette, both which happen to go through a lot of 3rd brake lights. And now my '14 truck is keeping up the tradition. That bulb was still in the open box, must of been sitting in my stash for 10yrs.... Jeez, but I used it today. Just means I sit in traffic a lot.... Cost me $0 and 5 minutes. I already got it working, simple as could be. Proof of why you should do a functional bulb check at every oil change and hang on to everything.

Edited by FL335i
Colossus Senior Enthusiast

Colossus

Posted
Posted

Replace it with an Philips, GE, or Sylvania brand LED (as well as your license plate lamps) and never think anything of it again :)

fbachman Senior Enthusiast

fbachman

Posted
Posted (edited)

my '07 had tremendous 3rd brake light assembly moisture issues. At one point, I replaced the whole assembly. The rubber seal on those is tricky and easily crimped, or installed where the rubber seal "slips" inside the race and gives a poor-to-no seal.

 

In fact, the third brake light assy on my '07 caused a significant leak once that showed itself as a puddle under my drivers side floor mat. Also stained my headliner pretty bad. Worth checking often.

 

 

Not sure if the approach on the later models is any different. Hadn't had a chance to crawl up there and look.

Edited by Grumpy Aero Guy
JimCost2014 Senior Enthusiast

JimCost2014

Posted
Posted

luck was on your side, my 2008's 3rd brake stopped working. I replaced the whole light assembly and still nothing, the problem ended being the fuse slot in the main box under the hood went bad. not the whole box, just the one slot for the 3rd brake light fuse, had to replace the whole unit for $550.00.

  • 6 years later...
HarrisonA New Member

HarrisonA

Posted
Posted

2016 Chevy Silverado 3rd brake light not working. Tested fuses, bulbs, all of it. We’re down to tracing and checking relays. No power. New bulbs but no power there or the license plate lights either. Ideas? 

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

  • Latest Articles

  • Posts

    • PhilB
      PF63 Oil Filters Going Away?

      By PhilB · Posted

      You can find PF63 and PF63F filters on Amazon https://www.amazon.com/ACDelco-PF63-GM-Original-Equipment/dp/B09RHSDX81/ref=sr_1_1?crid=4OQX91JYDO1T&dib=eyJ2IjoiMSJ9.YeKFFwDlEvIq8NtpzDXKZOYPE9Wb7dOhD81-cFJvM0UmP0YfeDVQ2KBAKGcPO4qEk_XMyhnRTBxTOGs7NPx8_zQMSeHZQp2ioF-ygHilLtuPs9irwf0K_rmLcWZogdRQrqidMUXW-LDj6d18aYD_ef7p4XBz25hp_LY0T_cl3tAmR8BoI48O854GOLinHwWJVGVhHAXuh1mhk7yVDbemx_TFNK-o53cBpdZJesAYu3U.7eKSD6sp5m7HKQHl8QuhX4E2_SoJAxuJDXosdcBDqzY&dib_tag=se&keywords=pf63%2Bacdelco%2Boil%2Bfilter&qid=1787057919&sprefix=pf63%2Caps%2C159&sr=8-1   https://www.amazon.com/ACDelco-PF63F-Filter-Assembly/dp/B004SIUREE/ref=sr_1_14?dib=eyJ2IjoiMSJ9._0V3idoBxN_3zdTkN3NoGAMq7e2ppPolmaO9ULwdFauE4HoFZHTYwbRycKmVkEy3ZWxFVHKrT9shU_yT821_pSLNmO4koGvxSS0zHK1bdoGEpIu2v9pV3Wz1kuSNXJBD9oau4SkVDh9-Xk1TTxbwDgvG7Y9L_nfeDhpYnQwF1SRz5JPvYzDZxu7PDW2xhYgJm_BWgHia9L0Yw3A8p9FgqVvORS7U7zq6Uh-SnZbPj5JRS-7rI1S5_R_4z4_QBQXwOWBbHdj26igibYN0JcABpgTRyuqNvoA3igX9mzi1F-Y.Nhnl9Y2T9htYr47bKYSdQ96qHIhjqeLcpD0nyIIszfk&dib_tag=se&qid=1787058550&refinements=p_123%3A213202&rnid=85457740011&s=automotive&sr=1-14&srs=21393605011  
    • Matt Parker
      Clunk when putting truck into drive and reverse.

      By Matt Parker · Posted

      I have a 2000 Silverado 1500 LS, whenever I put it into reverse and also in drive it clunks, the truck also feels sluggish when driving. Any advice/ideas ?
    • richard wysong
      Needing this part.

      By richard wysong · Posted

      Looks like it's riveted to me. What is wrong with that 1? Welcome to the Forum!
    • Grumpy Bear
      Some Assembly is Required

      By Grumpy Bear · Posted

      Missing pieces of the Assembly   Detergency vs Solvency   Not the same thing. Detergency is the mechanism that surrounds solid particulates preventing amalgamation. Usually accompanied by a Dispersant whose job it is to keep those encapsulated particles in Suspension. Solvency keeps things that can be dissolved in solution.    Salt is a solid that can be dissolved. Pepper is a solid that cannot be dissolved. A detergent/dispersant is effective on pepper but a solvent is more effective on salt. As long as the solids remain in either state, dissolved or dispersed then they can be be removed with the oil upon change.    How many wranglers does it take to herd cats? Depends on how many cats your herding. How much sponge does it take to soak up water? How much water is there to soak up? Point is most oil blends start with some herding ability and next to zero sponge and recently even fewer wranglers are being sent to do the same job.    So you start with a dozen cowboys and zero cows but at the drive progresses you pick up cows along the way, but not cowboys. At some point you have more cows that the wranglers can handle and some leave the herd. Deposits. And the API has an acceptable number of cows they are willing to let loose. In the ideal world zero is the right number for he rancher but to the butcher....a few lost is fine. This cow is beat to death. Let's move on....   Solvency isn't something oils on the Walmart shelf care about AT ALL. Problem is, you motor does. Fuels driven varnish sticks rings and only a solvent can keep them in check. The bet is that the solids driven portion that plug the expander rings and the oil drain backs and VVT screens and AFM screens will be an issue long before varnish is. Not that it wont be but if they market well enough the consumer can be kept ignorant enough to either believe it is "normal" (A quart in 1 or 2K is normal) OR is kept at bay longer than the first owner is likely to hang on to the unit. Solvency cost money.    Now the OEM's have John Q. Public buffaloed into the belief that the number cows accumulated along the trail is a known and predictable CONSTANT. It isn't. Nor is the rate at which they crossed paths with them. Only the number of wrangles is constant. Or was. Each new generation of oil sees fewer and fewer of them.    So what happens when the number of cowboys is lower (lower TBN) with each seasons trail but the trial is longer (OCI) and the number of cows along that trail continues increase? (Conditions that promote deposits).    For awhile the blenders were on to something. Better bases are harder to degrade (fewer cows) but that was overtaken by a longer trail (OCI) and improved breeding (More cows) while continuing to reduce the cowboy staffing levels (TBN/Aniline #).    Marketing has been successful. We've fired most of the staff, cows breed line bunnies, the trail is ten times longer and we've convinced the boss his ranch is in better shape that it ever was.    That kids is just the cleaning side. The side few pay attention to.     
    • davester
      Needing this part.

      By davester · Posted

      hit a junkyard.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...