digi2t

Hi all! New 2004 C5 owner, second post.

We've had the Vette for about a month now, and I quickly noticed that often times some folks would come zooming up behind me, and brake at the last minute. Either they're not seeing the back end of the Vette (it's matte black), or it's too low. Or maybe both. Anyway, I've been building electric guitar effects for several years now, so I decided that a DIY third brake light flasher was in order. A quick Google search, I found this article;

http://www.sentex.ca/~mec1995/circ/motflash.html

It fits the bill, flashing on the initial brake application, and then going steady (road rage avoidance measure). As an added bonus, there are two trimmers incorporated in the circuit; one to set the number of flashes, and the other to set the speed of the flashes.

Anyway, for those that are handy with a soldering iron, it's a fun afternoon project. The article offers an etching layout, for those that can etch their own boards. Personally, I'm a big vero (aka strip board) freak, so I did a vero layout for it. I used an aluminium Hammond 1590B enclosure to house everything, but a smaller plastic box will do as well. Here's the layout;



And, some pics of the (almost) finished product. I'm still waiting on the output connector that connects to the light.







The leads are about 8" long, which will allow me to velcro the enclosure to the forward bulkhead behind the bumper, and still easily plug into the light. The leads are epoxied on the inside of the enclosure, and hot glue prevents vibration from shaking/breaking anything loose.

The unit is PnP using Delphi connectors, so no hacking the harness. The proper connectors are available at Ballenger Motorsport.

Male connector (between harness and flasher module);
http://www.bmotorsports.com/shop/pro...roducts_id/861

Female connector (between module and light);
http://www.bmotorsports.com/shop/pro...roducts_id/852

Yeah... there are ready made units galore on the market, but if you're like me, and like the satisfaction of saying "I made that!", then hopefully this will put a smile on your face.

As soon as I have it installed, I'll post a video of it in action.

LoneStarFRC

Looks like fun.

Now design in a repeat timer capability. The commercially available unit that I have installed, only allows the flashes to occur once every 15 seconds. Keeps the flasher from going off every time you apply the brakes in heavy, or stop/go traffic.

digi2t

Yeah, I saw that, but decided that I really don't need that extra function. Considering where I live, and the amount of time it spends out of the garage, the chances that I'll be stuck in traffic are pretty remote.


However, your point is valid. I'll look into it. I think it might be an easy mod to the existing circuit, and a quick redraw.

LoneStarFRC

Between the CHML flasher and my sequential turn signal full LED tail lights, there's all sorts of fun stuff going on when I slow down and make a turn at the same time. Everything plays well with each other though. No issues.

sean.b

shouldnt be hard to work in an ic555 as a timer for the blinking so that it's not continuous.. right? just started screwing around with actually knowing what im doing with electronics, but that sounds right.

mrmagloo

Nice 2nd post bro.

digi2t

OK folks, slight (yet important!) update...


First off the proper connectors are as follows;


From Ballenger Motorsports -
Female (light) side - Part # CONN-75642
https://www.bmotorsports.com/shop/pr...roducts_id/852
Male (harness) side - Part # CONN-75646
https://www.bmotorsports.com/shop/pr...roducts_id/861


These are kits that contain the necessary pins, and seals, including one spare of each. I just wanted to reiterate this, since I ordered the wrong female connector the first time around.


Secondly, when I initially tested this on the bench, I used a 9v battery, and it worked fine. Unfortunately, once plugged into the car, it wouldn't flash, only come on steady. I traced the problem down to resistor R8, which provides the bias for the 2N2222 transistor. The cars system voltage is anywhere between 13 and 14 volts, which was sending the transistor into saturation, not allowing the base voltage from the flasher section to "do it's thing", so to speak. Anyway, I swapped out the 2.7K resistor for a 27K resistor, and all is well in the universe. Works as advertised. NOTE OF CAUTION... the resistor value here may be dependant on the gain of the transistor as well, so if you're planning on building this, I recommend you have some resistors on hand, values 2.7K to 33K. Start with a 2.7K resistor, and if the light only comes on steady, go higher until it starts flashing on power application. Better yet, use a 100K potentiometer, and dial it up until it starts flashing when power is applied. Then remove the pot, measure the resistance with a DMM, and insert the closest resistor value that you measured off the pot.


I have mine set up for 5 quick (about 1/3 second apart) flashes. Just enough to get your attention, but not aggravating on repeated brake applications. Then again, around these parts, folks are pretty tolerant. In other parts of North America, I understand that it might get you shot, so caveat emptor.

JohnS3

Awesome mod! I will be doing this mod on my C5 as the 'crazy yahoo driver's' in So. Florida like to tailgate & draft, but instead of making the flasher myself (Since my electronics workbench is currently dismantled) I will be using the M1 module... http://www.3rdbrakeflasher.com/brake...del-p-181.html Thanks for the info!

JohnS3

OK, I made the flasher using the M1. Wow! What an easy mod! I set the Re-Activation delay for 10 seconds of no brake use in order to not distract in stop-n-go traffic, and 3 semi-fast flashes (in 1 sec.). That M1 module is the bomb! About the size of a postage stamp, fully encapsulated and completely waterproof when used with the above mentioned connectors which are waterproof. THANKS digi2t for the link to the connectors! It made a professional install...and, it's plug & play! Worth every penny of it and the time to assemble it.

Skyhawk23

Hello JohnS3,

I have one of the M1 module also. But didn't work for me.

I have follow the instruction per the web site and splice the wires as per instruction. Got nothing.

Any special tip you can pass my way?

Thanks

JohnS3

Hmmm...Yes, you have to make sure the ground side/wire is connected to the LED light, the module AND the ground/black wire from the female (wiring harness side) connector. I had to add a wire to do this and splice from the black wire on the M1 module to the connector/led light side. Their instructions are not very clear as they show the M1 connected directly to ground. That won't work. If you look at the schematic on their instructions on page 2, envision connecting the 2 grounds together (the M1 ground point and the bulb ground point) and then adding a wire to connect that to the source connector (harness side) ground. I hope this makes sense. Also, watch the video on their website for excellent programming instructions. Let me know. I can draw a picture if you need me to.

Skyhawk23

JohnS3,

Thanks I will take a look at their instruction again, and maybe the video again.

JohnS3

Here is a drawing showing the ground splice...

Skyhawk23

JohnS3,

Finally got a chance to look and work on this again. Works like a charm, I think it is a combo of bad unit and bad instruction on their website. LOL

Thanks again.