I want to see if I could tap into a Black / Yellow brake light wire around the pedal area inside the car. I am using a led stripe for the third light and I want to keep everything in the inside of the car. I don't have any wiring diagrams so I was looking for some help. I aleady tested it all out back at the tail light terminal and it all works fine back there. I tried a tap and the light is constant on and no affect when I push the brake pedal. Not to protectant in the electrical areas.

I need to run a third break light for my compliance, was looking at running the wire from one of the rear tail light units as there are push on electrical fittings so just need the add a piggy back fitting which will easy then run the wiring as discreetly as possible with the existing wiring loom to the third light, I'm looking at interior third light so will be able to run the wires behind rear panel (behind seats). I would rather not have to do it but our laws state I must.
Let me know what you end up doing.
Steve

You could be hooking into the wrong side of the switch?

Looking at this diagram for a '73 (not sure what year yours is), there is a black/yellow wire coming from the fuse panel to the switch, and then another black/yellow wire from the switch to the brake lights. You probably tapped into the one coming from the fuse panel. Try the other one. (35 is the brake light switch, and 14 are the brake lights.)

http://www.pelicanparts.com/914/parts/Elec...lectric_73A.jpg
http://www.pelicanparts.com/914/parts/Elec...lectric_73B.jpg

Also here are some more schematics for different years:
http://www.pelicanparts.com/914/914_electrical_diagrams.htm

I tapped my 3rd brake light into the wiring that goes into the brake light itself at rear of car. Simple and effective. The LED draws very little power.

That was it. I will post pics once I put it all together.I did some more reading and my brain clicked on.

Intercept the wire from the brake switch in the harness between the seats under the center tray.

Pigtail onto a brake light and run the wires up the harness to the rolbar or wherever the light is. 15 minutes and you're in business.

here is my instrux for giving juice to your 3rd brake lite from the rear lamp housing; look at the second picture

http://www.914world.com/bbs2/index.php?showtopic=212499

Got most of it done. I did this on my other car and really like it.With every other driver playing on their phone and SUV 's that cant see you it gives you a fighting chance not to get your classic rear ended.I also like how discrete it is when its not lit up.Most people would never notice its on your Porsche. Click to view attachment Click to view attachment