Write Up: flashing 3'rd brake light. Improve safety. Includes Diagram.

[db_autotek]

This write-up will explain how to make your 3'rd brake light flash during braking.

I've done this mod for many cars now, for myself and friends. It is growing in popularity for heavily modified cars for a couple reasons: we drive fast and brake hard, often modified cars are actually harder to see (lowered / custom lights / ect), it has proven to greatly improve the distance of tailgaters and the always annoying last-second-brakers. Yet I've also done this in a few luxury cars too, for basically similar reasons: it cuts down on tailgaters, dramatically improves visibility of your car during those torrential downpours, and just generally helps keep people off your a**. Believe me, you will notice a huge difference in that department. ---------Parts: *one Tridon flasher from your favorite auto parts store, should be model EP34-C, EP35-C, or EP36-C. The model will be important to remember, but either will work fine. *several standard electrical connectors (weather resistant male and female blade connectors and good quality butt connectors)*some red and black wire, descent gauge and quality.*some electrical tape and/or heat shrink tubing.*a few zip ties.*Optional: one 22K Ohm resistor (Radio Shack or wherever) and soldering iron.---------

However you wish to disassemble your brake light assembly and surrounding areas is up to you, depending on how deep into it you want to go. I strongly recommend removing the brake light housing, removing the parcel deck, and removing the trunk garnish by the fuel tank. This will provide the best access to everything and allow you to see where to zip tie everything in place.

Next, follow the diagrams and wire up the flasher. There are two ways to do it. The standard method will provide a fairly fast flash but can potentially cause your "light bulb out" warning light to come on. I did not have this problem, but I cannot promise that you will not. Also, it will not work for modified LED style brake lights, possibly including the simple replacement of your filament bulb with one of those 21-LED bulbs or the like. Adding a 22K Ohm resistor will fix these issues since it allows the system to think there is the appropriate load of a filament bulb. (remember LED bulbs use a fraction of the load of filament bulbs.) Another note, you can wire it up using the standard method and very easily add the resistor later if you have trouble or switch to LED.

VERY IMPORTANT: these diagrams are made for the Tridon EP34 model flasher, but sometimes that one is difficult to find. The EP34 uses the E blade for Ground (E = Earth = Ground). The EP35 and EP36 models use the B blade for Ground, so if you use those models then you need to look closely at the diagram and reverse the connections to the B and E. Thus, if you use the 22K resistor on models EP35 or EP36, you will need to solder it between the B blade and the L blade.

Standard Diagram:

Modified Diagram:

I strongly recommend using spade connectors throughout the whole project so that you can un-install easily or make it easier to replace a flasher if you ever have to. Make sure to use good quality weatherproof connectors to keep things clean and safe. When it is all wired up, I recommend using some heat shrink tubing or split loom on all the wires to give it a stock look.

One extra little touch that I do: take about a 6-inch by 6-inch square piece of Dynamat Xtreme and wrap the flasher unit. (in reality you can use any sound dampening material, I just happen to have a few pieces of Dynamat laying around usually.) This does several things: mostly to silence the "click click click" of the flasher, which is audible even though it should be mounted in the trunk (as opposed to right under the parcel deck garnish). Also, it protects the unit from extreme heat and cold, and provides excellent vibration protection for those who have subwoofers.

The last step is simply to zip tie or screw the flasher unit under the parcel sheetmetal inside the trunk. You could also use double sided foam tape or some industrial velcro if you plan on working in that area alot. ---------

I've only had to replace one bulb and zero flashers, But you should keep an extra bulb in the car since the flashing does reduce the life of filament bulbs. LED bulbs shouldn't loose any life.

My final notes: Some would argue that this modification is illegal, and technically that is correct. But I've never been pulled over and neither has anyone I've known. On the contrary, Ive received complements from many people, including one officer, that it was a great safety modification. Finally, it shows people that you actually care.
Modified by db_autotek at 8:40 PM 7/3/2008

[maxnix]

Well, I hate to attract unwarranted attention from the gendarmes.

However, when the CHMBL (after all, using the brakes does not necessarliy indicate the vehicle will come to a complete stop, thus I still use the original acronym), the original standard had the light flash with increasing frequency as negative G forces increased.

This was deemed too confusing for the average American driver and was deleted from the standard.

[Razi]

These was deemed too confusing for the average American driver and was deleted from the standard.

[MinisterofDOOM]

Great writeup. With all the last-minute brake-slammers these days, it's definitely a tempting mod.

This was deemed too confusing for the average American driver and was deleted from the standard.

Humorous as that statement is, I believe the real reason for not using flashing brake lights is that it would conflict with existing US regulations that restrict flashing red lights to emergency vehicles only.

[db_autotek]

That's true, it is technically against DOT regulations. Only authorized emergency vehicles are allowed to have flashing red, white, or blue. For the rest of us, the only authorized flashing color is orange.

But that said, I've only received compliments on it. Really I got the idea from the motorcycle guys. Many of the cruisers and choppers use flashing brake lights, and a growing number of sport bikes are doing it too now.

Another option I have started to see in the last year is the Triple-flash-to-solid brake light mod. That might be a little bit more acceptable. When you apply the brakes, the CHMBL flashes three or four times and then goes to the standard solid. Those kits can be purchased, but I think they are technically for motorcycles. Of course they could just as easily be used on the CHMBL.

I personally will continue to use my original flasher. I always have dark window tint (without the CHMBL cut out) so for me there are nothing but good reasons to do this mod. I would recommend it to anyone, and if you use spade connectors in all the right places, you can undo it anytime if you do not like it.

[maxnix]

Humorous as that statement is, I believe the real reason for not using flashing brake lights is that it would conflict with existing US regulations that restrict flashing red lights to emergency vehicles only.

Maybe, but first thing one has to realize is the lights are on th rear of the vehicle and in front of any affected observing drivers.

Secondly, if true, then pumping ones brakes would be illegal, and this is required on non ABS equipped cars at high braking forces when any wheel locks up, or even just on an slippery surface.

[qship96]

Keep in mind many vehicles have red colored rear turn signal/hazard lamps also, including most new Infinitis.....why they switched from amber is unknown, and seems a backwards move as far as safety.

[unknown007]

Keep in mind many vehicles have red colored rear turn signal/hazard lamps also, including most new Infinitis.....why they switched from amber is unknown, and seems a backwards move as far as safety.

I think all red rear signals are best.Amber ones suck!

[maxnix]

Keep in mind many vehicles have red colored rear turn signal/hazard lamps also, including most new Infinitis.....why they switched from amber is unknown, and seems a backwards move as far as safety.

It most definitely is!

TUV (Deutshcland) and other Western European countries require directional change lamps to be amber so at a distance and high speed one could distinguish between a change of directions vs. deceleration.

Way too rational for NTHSB who took 20 years to catch on to the wisdom.

[db_autotek]

Yeah after thinking about for awhile, I realized that some older and newer cars have red turn signals. I think, as most people do, that the all-red looks best. But above 90-100mph or during bad weather, the amber is dramatically more visible than red. I've even seen some Volvos with white turns in the rear, with the factory housings. But they may have just mistakenly put in clear bulbs instead of amber. You know what I can't stand though? Green bulbs in the turns.. Usually you can see those on cars with the .99 cent NoS stickers with no NoS.

[maxnix]

White bulbs in clear indicators fubars the whole business.

Green is purely retarded, but is looks so keeuuuwwelllll.

All red was common in imports until late 1970's - early 1980's.

[greenwar]

Saw a corvette tonight with flashing 3rd brake light. I hadn't seen that before other than in bikes. I looked cool and also was very visible.

[MinisterofDOOM]

I've even seen some Volvos with white turns in the rear, with the factory housings. But they may have just mistakenly put in clear bulbs instead of amber. You know what I can't stand though? Green bulbs in the turns.. Usually you can see those on cars with the .99 cent NoS stickers with no NoS.

My dad has mentioned a few times some of the ODD lamp color combinations he'd see on cars in Mexico (speaks spanish so he translated for company stuff there). There would be greens, purples, blues, random lights glued all over like a badly decorated big rig...obviously regulations were lax.

As for cars in the US with factory white signals, I can think of a few. There was a mid-90s Suzuki or Isuzu or one of those lesser Japanese brands that had white rear signals. Some other same-era Korean car had them as well if I'm not mistaken. I've seen enough of them to be pretty sure it's not a case of wrong bulbs.

Keep in mind many vehicles have red colored rear turn signal/hazard lamps also, including most new Infinitis.....why they switched from amber is unknown, and seems a backwards move as far as safety.

Yeah, I'm not sure how the "law" works. I just remember reading an article about Mercedes Benz (IIRC) trying to get NHTSA permissions to use their stock flashing tail lamps here in the US and being denied, supposedly for the reason I stated above.

I don't really think red signals are a bad thing. With the CHMSL, any question is answered pretty quick, unless someone lets the lamp die, but that can screw up any setup.

One MAJOR complaint I have with newer car light designs, though, is poor front signal visibility, especially if the headlights are on. A lot of new cars have the front signal buried in the stupid new massive headlight housings instead of out on the corner where it should go. It's hard to tell what people are doing at intersections when all you can determine is that someone's insanely bright headlights are turned on in front of you.

The other day I was behind an SUV with a cheap receiver hitch light. It flashed with the turn signals instead of staying solid with the brake lights. Very smooth.

[db_autotek]

One MAJOR complaint I have with newer car light designs, though, is poor front signal visibility, especially if the headlights are on. A lot of new cars have the front signal buried in the stupid new massive headlight housings instead of out on the corner where it should go.

Agreed completely. My parent's new Fusion comes to mind.. Just for "looks" then maybe it looks better within the main housing. But for visibility, it should be separate and wrap around the side just a bit. I saw an amazing LED headlight setup on an Aston Martin. Not sure which Aston Martin, they kinda look the same if you're not very familiar with them.. especially when they're blowing by you.

[maxnix]

Saw and RX350 the other day, clear signal lenses, yellow bulb.

In the bright sun, I coiuld not tell she was signaling until she was right on top of me, then just barely if I stared. So stoooopid!