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3rd Brake Light

sc4808

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sc4808 Enthusiast

sc4808

Posted
Posted

The 3rd Brake light on my truck fashes for a few seconds (10 sec or so) when you first put your foot on the brakes and then goes to solid.

 

I have been watching other GM trucks on the road and have ony seen 1 or 2 others that do this. I have seen it on cars and other brands but not many GM trucks.

 

I am curious as to why a few trucks have this feature and others don't. It is not listed as an option on the window sticker that was on my truck. Was it something that they did for a short while and then quit or was it some sort of experiment by GM?

 

Any info would be great.

crazymjb Enthusiast

crazymjb

Posted
Posted

Are you sure its not decceleration or breaking speed sensative. I know BMW uses adaptive break lights, and that my father always said to put on the emergency lights during quick braking.

 

It is also my understanding that their are aftermarket modules which do this.

 

Regardless I think it is a great idea. Sorry I couldn't be more helpful.

 

Mike

sc4808 Enthusiast

sc4808

Posted
  • Author
Posted

Mine will do it even when the truck is parked and the brake pedal depressed so its not a deceleration thing it is simply a flasher wired into the third brake light circuit that times out after 10 or 15 seconds.

 

I take it that this is fairly rare then, I wonder why my truck came that way?

 

I like it too. Does anybody elses truck have this feature?

Guest chevydeerhunter

Guest chevydeerhunter

Posted
Posted

Hmmm....I just checked mine and it doesn't do that. I've only seen a few that do. Beats me.

MS3DALE Senior Enthusiast

MS3DALE

Posted
Posted

I can tell you one thing for sure,It's not any kind of option that is offered by GM.

As far as I know its not supposed to do that unless the driver is "pumping" the brakes,which would of course make the light flash on and off.

I also checked for bulletins from GM on this issue but could not find any.

MountaineerTom Senior Enthusiast

MountaineerTom

Posted
Posted

Did you buy your truck new?

 

I've seen a kit that you can buy and add to the third brake wiring that will make it do that.

 

If you bought it new and didn't put one of those kits on, then I don't know why it would be doing it. Unles the dealer instaled it for some reason.

Nice rig Enthusiast

Nice rig

Posted
Posted

Sounds aftermarket to me, I read a while ago about a kit that has the 3rd brake light flash for a few seconds before going solid. :thumbs:

RyanZ71 Senior Enthusiast

RyanZ71

Posted
Posted

I always find it silly and annoying to see a truck or car that has that option on it. Really gets annoying in rush hour traffic! Makes me wanna roll down the window and yell "Hey you dumb redneck! you put that on because you got tired of people crashing into the back of ya huh?!" :thumbs:

sc4808 Enthusiast

sc4808

Posted
  • Author
Posted

I bought my truck new, it came like that from the factory, not a dealer add on and certianly not added by me.

 

It is not me pumping the brakes, it has some sort or circuitry that makes the light flash for 10 to 15 seconds and then goes to solid. Once the light stops blinking, if you lift your foot off of the brake and press it again, the sequence starts over again.

 

I was hoping someone would know how many trucks came like this and why, was it an expiriment by GM?

MS3DALE Senior Enthusiast

MS3DALE

Posted
Posted

I have been behind a lot of '99-up Full-Size GM trucks and have yet to see one where the third brake light flashes,So I have noooo idea on this one.

c4cruiser Enthusiast

c4cruiser

Posted
Posted

I've never seen this either. Did you ever replace the original bulb at some point?

 

Adding a separate flasher and wiring could be a job to do and it may be that there are complete bulb assemblies that have a flasher built in. It would be a plug and play operation.

 

If it did come as a factory installed item, there probably would have been something listed on the window sticker. The CMHSL is a federal safety requirement and if it was different than other production vehicles of the same year/body/series, I would think that a flashing lamp would have been listed there.

sc4808 Enthusiast

sc4808

Posted
  • Author
Posted

Nope, never changed the bulb. There was nothing on the window sticker that mentoned it (I still have the sticker in the glovebox).

 

It is beginning to sound like I have one of the only ones that came this way.

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