Fading brake lights [Archive] - DodgeIntrepid.Net Forums - Dodge Intrepid, Concorde, 300m and Eagle Vision chat

: Fading brake lights

02-28-2005, 06:31 PM
Has anybody seen this done to a car before? My friend just wired his brake lights so that when he steps off the brake it fades out.

02-28-2005, 06:57 PM
I have never seen anything like that but doesnt seem like it would be too hard to make with some capacitors and such.

02-28-2005, 07:07 PM
yeah he used a relay and some power caps. It took him a shitload of time(i mean several hours) to figure out and then do.

02-28-2005, 07:14 PM
I remember seeing that BMW or something had brake lights that were of varying brightness depending on how hard you pushed the pedal, that was mega cool.

Did he make a schematic he can scan or just kinda winged it?

02-28-2005, 07:18 PM
He just thought it up in his head and tried to figure out how he would have to do it, and was wingin' it. He said that he'll do it to my brake lights if i want him to. Shit a job like that would cost me a couple hundred but ill get away with payin him about 40.

02-28-2005, 07:18 PM
That's exactly how to do it. All you do is connect a large value capacitor in parallel with your brake light circuit (the plus terminal of an electrolytic capacitor to the wire for the brake lights, the negative yerminal to ground), and what happens is the capacitor charges up as the brake lights are on, and slowly discharges thru the brake lights when the pedal is released. You may notice a slight delay when you first press the brake pedal and the capacitor charges. You can actually "dial in" the delay time using a potentiometer across the capacitor to create what's known as an RC time constant (resistance times capacitance equals 1 time constant in seconds, and it takes 5 time constants to completely discharge a capacitor, most of the charge is lost in the first time constant; approximately 90% opf the charge). Another good idea may be to put a diode in series with the brake line before the capacitor to prevent the stored charge from going back towards the brake light switch and the turn signal circuits, just like the diodes on the third brake light. It could possibly come into play when you are stopped with your turn signals on but I'm not sure...

02-28-2005, 10:40 PM
I'm very interested in doing this... I plan on taping into the brake wire before it splits to the seperate lights... Where would I do this (in the trunk?) Also could anyone suggest the size of capacitor and diode.....(remember, I'd like to use just one on the main brake power wire)
EDIT: I posted a thread about this in 2nd Gen Mods HERE (http://www.dodgeintrepid.net/forums/showthread.php?p=637389#post637389)

I looked at radio shack... any better stores?

This wouldn't be big enough, would it??? (largest listed..)
4700F 35V 20% Axial-Lead Electrolytic Capacitor (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F004%5F001&product%5Fid=272%2D1022)

Largest diode I found was only 3A... good enough?

3-Amp Barrel Diodes (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F006%5F000&product%5Fid=276%2D1144)

03-01-2005, 09:34 AM
im not intrested. its going to freak somone out and your going to cause an accident. because there going to think your not stopping. then bam/

03-01-2005, 11:23 AM
I remember seeing that BMW or something had brake lights that were of varying brightness depending on how hard you pushed the pedal, that was mega cool.
Another variation of this, might have been BMW, was variable brightness taillights. I have never seen them, but from what I've read the brightness of the taillights is ajusted depending upon how ambient brightness and dirt or fog obstructing the tails.

03-01-2005, 09:20 PM
I don't see how this could confuse someone... the brakes come on the same (when I stop) but when I let off the brake (and start moving) they gradualy dim over a couple seconds. That should in no way pose a safty hazard should it?

03-01-2005, 09:45 PM
ohh;. i thought when you pressed the lights. they auto dimmed then came back on then dimmed again.

i like the idea of them dimming when you let off the brake. kind of like the insides. now why not the headlights as well :)

03-01-2005, 09:48 PM
Some one around my area has an Acura TSX and his middle brake light flashes quickly when he's light on the brake then when he presses to stop it just stays solid red. Ive been thinking about this mod too, but dont really have the time to do anything. Maybe you could see if all TSX's do that, and if they do rip out what does it and put it in your car.

Its pretty cool, since its like saying "stay of my ass i might brake".