Pressing Brake Turns off Clock/Dims Navi
 

Looks like I have a wiring issue somewhere. Anyone ever encounter this?

I press the brakes and the clock shuts off and the navigation map goes into night mode. I let up and it goes back to normal.

With headlights on, everything works normally.

Grounding problem somewhere?

Sent from my Nexus 4 using Tapatalk 4

Do you have OEM taillights?

Tom's

Oh and it seems to be intermittent. I just checked this morning and it worked fine.

Sent from my Nexus 4 using Tapatalk 4

Ghosts.. It's the only logical explanation.

That, or the dragons again.

Double check the connections on any aftermarket lighting. I don't know much about Tom's, but if it requires re-wiring that would probably be the first suspect. It's an off-chance, but LEDs also give off RF radiation that can interfere with electronics. Cars designed for them have fewer problems, but for instance, when I put aftermarket LED bulbs in my Outback they started causing radio interference (especially in the morning). I don't know if the stock lights are RF shielded (like speakers), but there's a good chance aftermarket ones aren't. Although I don't have any problem with my Valentis.

Checked everything out - looks like the Tom's tails were fine, it's my Phastek rear fog/fourth brake light that is dead, and for whatever reason, that dying caused weird things to happen elsewhere. Not sure if the bulb is toast or if something else is, but taking the bulb out of the Phastek socket made everything work like normal again.

Bulb doesn't looked burned out, it's a Sylvania 3157K which goes for about a buck, so I'll pick one up and see if that solves the problem.

Sometimes being an early adopter isn't so much fun.
Google brz wiring and click first link,
Page 148 onwards
The part where you say everything works with headlights on concerns me
Get rid of the rear fog lamp and toms and revert to oe and tell us what happens
Have you disconnect battery and retried?

something is touching ground from physical contact when you press the brake.

I could walk you through the steps to try and narrow down the source (I did this with many pinball machine malfunctions), but you have a warranty!!

Have you checked brake (the call it 'stop' ) lamp fuse? Or whatever you tapped phastek gizmo into?

The bulb out might indicate overvoltage. If the next one blows quick theres a hot wire touching the positive wire the lamp.

If the bulb never works there's a dead short.

Take it to the dealer you have a warranty. Remove all electrical mods including the tails first. The isuse might disappear.

Replaced the fourth brake / rear fog light bulb and now everything works as expected. I'll keep an eye on it to see if there's an underlying problem.

Thanks for all the suggestions guys!

You needs a diode somewhere I suspect

I knew you had aftermarket taillight mods and that they were causing the issues. I can tell you the only time I have ever seen this issue and it did the exact same thing was when I bought a 1995 Acura Integra from a guy. On the drive home the dash lights would only light up when I hit the brakes. The idiot had placed the dual filament bulb in the single filament bulb housing and the single filament bulb in the dual filament bulb housing in the taillights. I figured it out once I got home. Once something that is supposed to be grounded isn't, the voltage can travel back up the wire till it finds something that is grounded.

Yeah, I've seen stuff like that too, but in this case, I've had these lights in place for months and the issue just started happening this week. The bulb is definitely dead. Does it sound right that a dead bulb would cause grounding or other wiring issues?

If in the proccess of dying it got too much current or something melted such as some contacts then it is possible. What did the dead bulb look like inside?

The filament looks intact. I don't see any abnormalities anywhere but connecting it to voltage shows that it's dead.

Perhaps a short inside the plastic base that I can't see from outside?

Sent from my Nexus 4 using Tapatalk 4

That would be my guess. I would be worried about the design of the wiring that is feeding it as it may just happen again in the future.

Sorry for bringing up an old post. I am having a similar issue. I installed the phastek 4th brake light kit using the tap connectors supplied. It has been installed for years. I havent noticed any issue the whole time. I recently realized it wasnt working.

Assuming a burnt out bulb I bought a new sylvania silverstar bulb which is what the kit came with. Still didnt work. I purchased a harness that connects to the brake light that has wires coming off to connect to the 4th brake light instead of taping into the stock wiring. I removed the old connectors verified only insulation on wires were damaged and shrink sleeved over the exposed portions and reinstalled with the new harness. Light worked again.

I then noticed that when I hit the brake it dims the clock and turns the aftermarket head unit backlight on. This seems to correct if the headlights are turned on. I removed the wires from the new harness and it fixed the problem. I then removed the bulb and this also corrected the problem. I tried the second bulb in the package and even the old bulb and had the same issue with them all. Is there a special bulb to use to correct this issue? Or am I stuck living with it or not having a 4th brake light?

I'll guess that the incandescent bulb load takes the whole system over the top. Try using an LED bulb instead.