Okay...so I originally thought about posting this here 6 hours ago but after some searching online and reading a few different threads, decided to take some other advice instead and it seemed pretty legit, figured I wouldn't waste anybody's time here. Well, turns out it didn't work, so here I am again...

The truck is a 92 Dakota and I wired up a 7 pin trailer brake control system. Obviously, I nailed the basics, brown wire is running lights, green wire is right turn/brakes, yellow wire is left turn/brakes, white wire is a ground, and blue is the feed from the brake controller. The black (aux 12V) and purple (rev lights) weren't used in this application.

The problem is the brake controller itself. I got the black wire (12V fused feed) for power, the white wire for neutral/ground, the blue wire for the brake output signal, but the red wire I can't seem to figure out which circuit it taps into. I was told to wire it on the switch side of the brake pedal which made sense because when the pedal is depressed, then the red wire should get power, but that isn't the case here. It has power anytime the connector for the brake light switch is plugged in now. When I initially checked it with a test light, it only worked when the pedal was pushed down. But with the brake controller installed, it has power all the time.

I guess my question is did I hook it up on the wrong side of the switch? Or did I just hit the wrong wire all together?? On the switch side there is a 6 pin connector with 6 wires coming off of it. On the feed side, there is the same 6 pin connector but it has 9 wires coming off of it. Does anyone know which wire to tap for the red trailer brake control off the factory harness?? I'm at a loss here and really don't want to hack up the factory wiring trying to chase this one down. Any help is very much appreciated

 

What brand brake controller are you using? Pics are always helpful too.
I have a 7 pole connector and brake controller on my '92. The p.o. towed a fifth wheel RV.
I recently used a flat four adapter to tow a boat trailer (no trailer brakes) and the lights worked fine.
I won't be able to check my truck closely for you though, until next week (family wedding etc etc.), but will let you know what I find.

 

The brand is a Drawtite but I don't think that really matters. Most vehicle styles I have seen like this one, Tekonsha, U-haul, Whatever brand Wal-mart sells, etc. are the same wiring. Black is fused power to the controller, Blue is feed from controller to the brakes, white is ground and red is the dreaded open end of the stop light switch circuit. Unfortunately, I'm a very impatient person and already figured the answer out earlier this morning. The red stop lamp feed to the aftermarket brake controller splices into the white wire with a tan/light brown tracer on the vehicle end (not switch end) of the (6 pin/9wire) plug for the stop lamp switch. I scoured the internet for the answer to this all last night and this morning with no luck. Hopefully someone can pin this or do a better writeup in the trailer towing FAQ section for future reference. It is literally nowhere to be found. Everyone shows where the wire goes, but there is nothing that shows a diagram from the truck side with the color of the wire for a 92 dodge dakota.