Just noted the following at Nissanhelp.com:

2010 NISSAN ARMADA; VOLUNTARY SERVICE CAMPAIGN TOW HITCH RELAY
Nissan has determined that the Trailer Towing Harness installed on some model year 2010 Armada vehicles may be missing one of the tow hitch relays. Without this relay, the trailer running lights will not function. Nissan is conducting this Voluntary Service Campaign to install a tow hitch relay at no charge for parts or labor.

This is a small relay that plugs into a harness under the dash.

Thanks scr38.
The diagram shows a removal of the lower dash for access.
I'm just going to hook up to my trailer first and see if the lights/brake lights all work.
Can't do for a couple of weeks becuase I'm away.

Most of these should have been caught at the dealer but some might have escaped.

DeepCat

Even easier, throw on the flashers and check for power with a test light at the plug receptical.

Cool - I'll do that. Thanks kgbrr

Is this the relay in question?
http://www.titantalk.com/forums/attachments/titan-general-discussion/64422d1218839416-2007-nissan-armada-trailer-tail-lights-not-working-image124.jpg

I recently hooked up my hitch connector and my running lights, flashers, brakes and turn sigs all work. I'm relieved. ;>)