Just installed my LED 3rd brake light. Went to tap the brakes and only the LED blinked not the tail lights.

I turned the headlights on, and my DRLS come on but still brake lights wont work. Just spent an hour search the forums, checking fuses, checking all wiring getting really pissed and was about to freak out.

Then I put the key in the ignition and turn on the ACC mode, hit the brakes and all brake lights function properly!!! WTF?

Any insight here? Brake lights always worked when the cars off before, do i need a resistor or something?

And i wouldve searched this but this god damn forum is so laggy I cant figure out why, tried on 3 different computers TERRIBLE search response time and laggy scrolling that takes forever!

 

Are your taillights both LEDs? If not, it could be because you don't have a resister on the 3rd brake light LEDs.

I don't know why it would be that, but it seems like the only logical explanation.

 

Also, if your car is equipped with cruise control it probably wont work either because you need a resistor for the 3rd brake light bulbs when you switch to LED. Weird chevy problems. lol

 

no cruise control, stock break light bulbs.

 

did you leave one of the stock bulbs in?

 

You might have a bad electrical connection somewhere.... or bad ground.... I have not had any problems with my retrofit so far.... I hope its not in the electrical under the floors that would suck :/ Maybe a Fuse? or Loose Wire?

 

gaurenteed this will be fixed if i get LED brake light bulbs, the LED 3rd brake is coming on faster than the tails so maybe thats screwing it up.

 

Diagram for a 2007 Cobalt

 

It's probably just the need of a resistor. If you get LED brake light bulbs and they still dont work, get resistors for them too.

 

This is actually a stock thing that is normal. when the car is OFF and you press the brakes ONLY the center light comes on. when the car is on ALL lights function normally.
I can post a video of this when i get home.

/thread

 

^ This, wow i thought more people knew this. its normal, once the key is turned from the off position, all brake lights work as normal.

The CC issue is only on 07+ IIRC. my 06 Doesnt have it

 

Thats how the car works...

/thread

 

My brake lights don't work when the car is off :/ 09 ss

 

how did it plug in? and did you leave the bulbs in the other two slots?

 

i got the kit from buy hids, just went in with two pins, didnt touch stock tails.


Very strange that this is how they work couldve sworn theyve lit up before when the key is not in.

 

need how to on this i set mine in there and it flops around did you glue it?

 

Bump.

Breds how the heck did you attach that circuit board into the tail light housing? there are no instructions or mounting parts and it isn't immediately obvious to me.

 

tape bro!!! just rolled circles of it. sits there fine!

 

Why people says this????????
I have cruise control and did not use resistor for led 3rd brake light. And my brake taillights are led with resistors. And everything works fine as it should... and yes my cruise control works.

 

There is like 2 how to's with pictures.....

 

I found one, which was drill a couple of holes and zip tie it. Did you find a different one?

 

i did the double side tape, i dont like to drill on parts lol

drilled
https://www.cobaltss.net/forums/how-...ht-led-201699/

https://www.cobaltss.net/forums/how-...version-27113/

mine on page 3:
https://www.cobaltss.net/forums/how-...13/index3.html

 

Awesome, thanks a bunch!

 

post pics of setup

 

I will when I finally get to work on mine. Won't be fore 2 more weeks now.