Need help with trailer lights

[E U G]

Just got pulled over today because my right blinker on my trailer doesn't work. It's not getting the signal from the 7-pin connection in the back. I did find a loose black and red wire, anyone know what this is (see pic)? It's not hot so I don't think it has anything to do with my blinker problem. It's also not the same gauge wire as the left blinker one that works fine. The loose wire is thinner.

 

Also, what does the orange plug do? there's a cap on it and it's unused. Is this for brake assist? I thought this was part of the 7-pin connection.

 

I checked the fuse box and I had a bad fuse. Replaced it, but still not working. Any ideas?

 

 

[harriss]

http://www.google.com/imgres?imgurl=http://www.cumminsforum.com/forum/attachments/towing-hauling/12103d1229058428-rewiring-7-pin-connector-wire-colors-7waytrailerend.jpg&imgrefurl=http://www.cumminsforum.com/forum/towing-hauling/103482-rewiring-7-pin-connector-wire-colors.html&h=335&w=522&sz=29&tbnid=Z9QHe-FF-X95lM:&tbnh=77&tbnw=120&prev=/search%3Fq%3D7%2Bpin%2Btrailer%2Bplug%26tbm%3Disch%26tbo%3Du&zoom=1&q=7+pin+trailer+plug&usg=__EaNt8Jx37AmFMMBYjoupTtwouTU=&docid=Cy-cnhnpx0hIEM&hl=en&sa=X&ei=K89TUNudJ_Hr0QH27IHQBA&sqi=2&ved=0CEoQ9QEwAw&dur=1284

[Downeast Johnny]

Get out your test light and, using the diagram Harriss posted, find the last place that you have current to the green wire, (and post's that supply that current to the green wire.)

 

My trailer light troubles are most often caused by problems in the trailer harness itself, (or corroded light fixtures from submersion), as opposed to the tow vehicle. (Unless the tow vehicle is an old hunk of junk).

 

A simple 12 volt test light will help you out a lot.

 

Good luck.

Edited September 15, 2012 by Downeast Johnny (see edit history)