Hi all, Happy New year.
I have a (new) used 05 G35X sedan (my 3rd, I love these cars).
I've had an issue with the 3rd brake light intermittently working and not working since I bought the car in early November. The dealership I bought it from (Chevy) has done a lot to try to get to the bottom of this. We even tried another 3rd brake light and it did the same thing, so it doesn't appear to be the light assembly itself. The Chevy dealer's last fix was some type of wire splicing which we THOUGHT was the final fix because the car has been great for 2 weeks. Last night the intermittent issue came back. Can anyone help? Again, it's not the brake light assembly itself, we know this much from trying another light installed. Thanks.

 

I'm guessing they used a used light to test it, and these cars are notorious for bad 3rd brake lights, but not for bad wiring to those lights.

Try this fix here: https://g35driver.com/forums/lightin...t-fix-dyi.html

 

We tried a used light assembly and when it was installed it did the same thing. All LEDs on or all LEDs off. Brake light comes on sometimes, then not at all at others. Should I try a brand new light assembly? The DIY fix is not one I am Really up for myself, I am ready to bring it to Infiniti but know I will get raped on the labor to figure this out. It's been at the Chevy dealer 3 times where I bought it and at my local mechanic twice.

 

I have the same exact problem, and I've given up on trying to find the cause. Ever since I got my G coupe in April 2013 it's been doing this, and since then I've just learned to ignore it. I even brought it to Infiniti for them to look at, but ironically when I brought it in, the brake light was fully functioning. We tried banging it and moving it around to see if the brake light would cut out, but it didn't. I've never been bothered by the police for having the brake light not working so I just figured I'd save myself the trouble of fixing if I don't need to.

 

Several years ago I had mine replaced with a new unit. The local Nissan where I do oil changes was able to order and replace the part.

 

I went to radio shack and swapped out the capacitor which worked for a bit then began working only when it was cold, during driving and breaking the unit would heat up and fail again until cooled or tapped. I then went and bought the prepackaged led strips from the cheesy accessories aisle that can be cut to length and placed them in the stock casing and spliced the two strips in. Not as bright but can be seen through my limo tint rear window and has always worked since. About $18 and finished in 15 minutes keeps from getting rear ended, and the chance of a ticket.

 

Replaced mine with an aftermarket unit sold here on the boards. No more problems at all.

3rd brake light issues are common for these cars. The culprit is a component on the board in the light itself., and no garantee a used or new light will fix it long term.

The aftermarket LED strip i installed has been running fine for 3 years so far...

 

where'd you get the aftermarket unit from? simple plug and play?

 

From here

https://g35driver.com/forums/exterio...placement.html

Unsure if they still make them.

Wasn't a direct swap, but was pretty easy to remove the brake light, remove the board and then insert this peice in. I think i bought a stripped down board and soldered my pigtail on. Can't remember.


I did it all from the trunk by removing the packaging tray.