It is the wire with the red terminal coming off the brake light switch or housing. I cannot tell as I cannot get all the way under there since I had rotator cuff surgery.

It looks like, without knowing and looking up that particular colored wire, the wire that feeds the brake lights That is if it is hooked up to the back side of the brake light switch like it appears to me

I am not talking about the wires with the tape on them. I am asking about the wire with the red plastic terminal down towards the pedal sticking out of the right side as you are looking at it. Ground????

I know this wire must be serving as a ground of some sort as I have blinkers, tail lights with headlights on but no brake lights. If I tap into the brown wire running to the back the brake lights will work on one side.

How does this make any since?

If I am reading the wiring diagrams correctly, it goes to the turn signal switch. My understanding is that the brake lights run through the t/s switch so your rear light will flash on one side while the brake light is on on the other side.

It is possible for a bad t/s switch to cause brake light problems.

http://www.mymopar.com/downloads/1970/70ChallengerB.JPG

Brake lite power comes from the brake lite fuse in the fuse box via a pink wire to the (pic) brake lite pedal switch & it is hot all the time (think hot pink). The "out" white wire which is hot when the pedal is depressed goes to the TS column harness. With the stalk in nuetral 2 "out" wires to the L/R rear brake lites are hot when the white "in" wire is hot with pedal depressed. Your wiring looks altered. Seperate the TS/brake column harness & see if the white wire and the 2 out wires in the col half of the connector have continuity with the stalk in nuetral/hazards off (they should). See if the white "in" wire on the body half of the col connector is hot when pedal is depressed. Jump fire to the 2 wires in the body half of the connector that go downstream & see if the L/R brake lights light up. You want the hot in wire (which should be pink) at the pedal switch to be hot all the time & see what's up with your colors. Holler back. EDIT The 2 cojoined wires, one is hot in from the fuse box and the other powers the dome lights (hot all the time) & both were pink (OE). The single wire that you are inquiring about is the switched 12V going downstream to the column TS/brake harness & to/thru/out the TS switch (where 2 wires are energized at same time for R/L brake lights) then to the dr kick panel harness then rearward to the brake lights on each side. Not sure why your colors are different

No expert, but that doesn't look factory. Looks like a terminal someone has added. Factory used those big square plastic cases.

There needs to be only one wire on each of the brake light switch terminals, the one on top has had an additional wire spliced on (thus the tape)...maybe for an aftermarket cruise control; the lower wire has had the factory wire connector replaced with a generic spade connector.

The mymopar diagrams show 2 pinks going into the switch, one is the power in from the fuse box and the other cojoined pink goes to the dome lights (so both are hot all the time). The single wire on the other side of the switch (on/off switched 12V) is a white wire that goes downstream to the TS/brake pull apart harness dangling under the column & is hot when you push the brake pedal to close the switch. My racing partner has a '70 challenger that I can check whenever I can get ahold of him (hard to do). It's original as far as wiring goes

Yep should have pink and white wires to the B/L switch.

Three guesses, and only guesses.
1: what John said
2: Trailer towing wiring
3: supplemental ground to fix some long ago problem.
The factory never used those terminals but with the age of the car, who knows what some mechanic did somewhere. He may have fixed some symptom but not the problem.
As previously mentioned, the brake lights go through the turn signal and four way flasher switch and I would look there for what may be going on in your car.
Craig

Well the ad on wire has power when the pedal is pushed and I think the guy was bypassing the turn signal switch. I found the factory white wire with the original plug under the dash. I verified 12v from the pink and 12v out to the white when the pedal is pushed down, but still no brake lights. I am thinking it is in the turn signal switch so i guess that will be the next thing I replace.

Does that make since?

seperate the under the column TS/Brake dangling pull apart connector & on the col half of the connector with your meter see if you have continuity between the white wire and the 2 brake lite wires with the TS stalk in neutral/flashers off & this checks the function of the TS switch/harness. (2) behind the DR kick panel seperate the pull apart connector & jump fire to the 2 wires one at a time in the downstream (rearward) connector half & see if the Dr/Pass brake respective lights are lit. Holler back. EDIT I reread your last post & yes that makes (perfect) since & it sure sounds like the TS switch is fubared & explains why they bypassed it as brake lights are more important than TS lights. With the TS switch/harness being such a pain to R&R definitely check it out first & go from there