Here's a fix to errors that the other revision was pestered with and overlooked. Such as led blowout would cause all lights to die when one string is blown/out and you turn the lights on with the brake engaged.
Adjusted LED to the specs of what I am working with. Adjust the LED specs and resistor values in comparison to yours accordingly.
Bypass resistor lowered and string resistor raised for stability of individual strings during dead LED events.
When you have a problematic string your lights will nearly be full bright. So be aware that everyone following you may think you are braking while accelerating...
These LED are being over driven with extra current, I'm okay with that, you might not be. If you don't want to overdrive them when pressing the brake then raise the Transistor resistor value from 13k up to about 19k.
When you change your current load for the strings, adjust your transistor resistor value so you don't blow all your LED if brake is on when turning only 1 set on. I find between 13K-19K is the range before choking the transistor in most cases.
Added a capacitor for led fade when engaged and disengaged. (stay with a kinda' low value because your brake lights are suppose to all come on at the same time say most State Laws).
One last thought, I recommend using 1 transistor per side of the car. That would be 2 total on the vehicle.
This is my original plan, I am not a premium member so I'm using an alternate tag to keep going and update this schematic.
This is based off of the 2009 Honda Civic I have in my garage. It has two sources due to a dual filament bulb. One wire for low that is constant on when your headlights are on. Another wire for your high brightness brake filament that is only activated when you press the brake pedal. Both of the wires share a common ground. This schematic is for hacking into those three wires directly at the tail light housing.
