trailer harness

LOL.. I remember my first day on the internet..

The Bargmann connector that came with my Pod from FR was a piece of junk.  It was slightly smaller in diameter than a regulation Bargmann.  It wobbled badly when inserted into the TVs Bargmann! In fact, it was so poorly made that I actually could insert the plug in upside down.
Luckily the TV's lights were not turned on.  When plugged in correctly, the plug flopped up and down, so much so that the 'key lock' sometimes would not hold.
Within a few trips, the flopping had broken some of the plug wires!  That is how I found out that FR does not follow SAE Industry color coding.
I went to my RV dealer and bought a replacement plug.  This one fit snuggly and was impossible to insert incorrectly.  So if your Bargmann feels loose and wobbly you probably got one of the 'bad' batch. 
Most products now come from China and they only use metric measurements.  If they need SAE measurements they use the closest metric tools in their possession. I think the Chinese manufacturer simply molded the connector to their next smaller metric and so the plugs were smaller than the SAE male connector on American TVs. I have even had Chinese SAE wrenches which were well made but were forged to the nearest metric measurement.  So the wrenches never really gripped SAE bolts etc. correctly.  I micrometered the wrenches and found that, for example, the stamped 1/2 inch box wrench was actually 13mm. Which meant that it was a sloppy fit and always tended to round off bolt heads.

While we are talking connectors and stuff.   My new Pathfinder has a factory tow set up with 2" receive and 7pin.  It comes prewired for brake controller and included a harness for that in the glove box.

On the tow package and charging.. look in the owners manual to see if any circuit breakers or relays need to be added. We had to instal one of each on our Expedition.