Trailer running lights stopped...going crazy!

I have a 2003 tacoma and recently started having a problem with my trailer lights. My left and right turn signals work, my brake lights work, but not my running lights!

My trailer running lights won't stay on. I have:
1)replaced the plug that connects to the trailer
2)checked all ground connections
3)checked the bulbs-(tested them with a battery)
4)check the wires all the way back to the connector
5)checked all the fuses

I don't know what else to do! I got frustrated and I wired the brown wire from the trailer connector directly to the green/red striped wire on one truck brake light. One my trailer the brakes work, signals work, no running lights and it's not a ground/fuse. How could the running lights not work on the trailer if the left/right turn and brake lights work? The running lights work on the truck. Any advice is appreciated!

 

Yes, my truck running lights work. The connector is a 4 pin connector from the truck to the trailer and it has LED's on it that light up when the lights are active. They are telling me that the running lights are not lighting up from the truck side. I don't understand how the brake lights can work but the running lights don't...

 

I have a multimeter and have checked the fuses twice. I have checked at the truck connections that the blinkers work, brakes work, but no running lights. I have been messing with the wiring and I think this is making things worse.

Things were working better but now...when I hit the left blinker it turns the flashers on the trailer, the right blinker does nothing, and the brakes turn the running lights on. Also when I'm using the blinker, the blinker stops when I start breaking. Going a bit crazy here!!!

 

Souds like a wiring/connection problem. Also, recheck ground. Easy way is use a jumper cable connected to the trailer and truck frame. Grounds cause weird stuff to happen.

 

Is it an aftermarket harness for the trailer?
Very possible the box has gone south.
These nutso things happen when the box fries....
Or if scotch locks were used to install the adapter the green goo could have come a knocking.

 

So here's where im at:


Left blinker works, right blinker turns the flashers on, brake lights work, no running lights.

If I could just find out how to fix my right blinker I'd be all set. Both blinkers are wired exactly the same...both connected to the right side blinker of my truck. I don't know why my right would effect the flashers and the left would be a normal blinker with the same hookup...