Where's the best place to find power for a center brake lamp?

[burdar]

Yep, we were all overthinking it.  I originally assumed the pedal switch controlled the ground.  Since it has power on one side of the switch, you just have to tap in to the other side.  I'd use a piggyback spade connector instead of a Scotchlok.

[dodj]

geeze simply use the wire after the brake light switch on the petal

Yup.
I'd simply splice into the harness at the driver's side wheel well. Close to where the light will be mounted.
If you make your connection under the dash, you will have to run another wire all the way into the trunk area.

[burdar]

But isn't the brake light going to flash with the blinkers if you tap into the line back in the wheel well?

[HP_Cuda]

Darren is correct.

You want to take it from the brake pedal switch because if you take a splice from the wiring near the kick panel you will get input from the Turn signal switch and you will have a blinking brake light in certain situations.

Which could be funny though!!!

 

[dodj]

But isn't the brake light going to flash with the blinkers if you tap into the line back in the wheel well?

I don't think so. Left and right don't both blink when your turn signal is on. But maybe.  I'll have to look at the wiring drawing.

[roadman5312]

Darren is correct.

You want to take it from the brake pedal switch because if you take a splice from the wiring near the kick panel you will get input from the Turn signal switch and you will have a blinking brake light in certain situations.

Which could be funny though!!!

 

                                                                   

[HP2]

Darren is correct.

You want to take it from the brake pedal switch because if you take a splice from the wiring near the kick panel you will get input from the Turn signal switch and you will have a blinking brake light in certain situations.

Which could be funny though!!!

 

Yup. Used to install these back in the '80s. We always had to go to the switch under the dash or you get the blinking light issue using the turn signals.

[roadman5312]

Motorcycles use center blinking brake lights.   Attracts more attention.   

[Aracer]

The piggy back spade terminal on the white wire terminal of the brake switch is a good idea. The light works great hooked up to the white brake wire, and it doesn't blink when the turn signals are on. I tucked a 22g NASA Teflon coated wire under the rocker trim to along side the seat and under the window rubber to #3 brake light. The optional switch is mounted in that hole under the dash next to the E-Brake, to turn it off for less attention.
      As I said before I want the Billit pedestal LED lamp for the package tray on the E-body. Since it will stick up over the window frame and be well seen. Hanging it window high would be a pain to see around. Thanks for the discussion.

The logic circuit for a trunk hook up.
https://www.amazon.com/Pacer-Performance-20-702-Black-Circuit/dp/B001S16Z7W/ref=sr_1_1?ie=UTF8&qid=1476859089&sr=8-1&keywords=third+brake+light+logic+box

[HP2]

Motorcycles use center blinking brake lights.   Attracts more attention.   

True, but tapping into a vintage brake light wire in the trunk won't produce a blinking 3rd brake light. It will produce a light that comes on solid when the brakes are applied and only blinks when that wire has a turn signal applied to it. 

[dodj]

True, but tapping into a vintage brake light wire in the trunk won't produce a blinking 3rd brake light. It will produce a light that comes on solid when the brakes are applied and only blinks when that wire has a turn signal applied to it.

What prevents the other original brake light from blinking?

[roadman5312]

[HP2]

What prevents the other original brake light from blinking?

The other brake light is on a different wire.  An 1157 bulb, which is all E body tail lights, has a  running light filament and a turn/brake filament. The wire supplying the brake/turn element in the bulb is energized on both left and right when the brakes are applied. When a turn signal is activated, it only energizes the  appropriate side. However, turn signals override brake lights going to this bulb so when you step on the brakes,  one  side lights up solid, the other  side blinks, if your turn signals are on while stepping on the brakes.

Hence, if you tap into the  brake light wire in the truck for a third brake light, you will get a solid brake light when braking only and an occasional  blinking light, depending on which side's wire you tapped into, when  flipping on the turn indicator.

[Chryco Psycho]

True
 the turn signal switch splits the brake light wiring into 2 separate wires , 1 for left & 1 for right so that it can interupt the brake light to blink for signal

 Not that it matters but on most euro cars they use yellow for signal & red for brakes so there is a different circuit for brakes so you can tap in anywhere

[duodec]

Not a specific recommendation for vendor, but if you do not want to run another wire from the dash area to the back, a current example of the logic module I mentioned is available on ebay, possibly also at RV/trailer shops, maybe even better auto parts stores.