All the lights on my Boat trailer function correctly EXCEPT the tail lights (Running Lights). I recently discovered why and have a few questions concerning this.

The reason I can see is because the Adapter plug I am using to go from a round connector on my truck,to a 4 pin connector on the trailer doesnt have a provision for tail lights(running lights) Please see pics to understand what I am speaking of.

So because this adapter doesnt have the provision for running lights,does this mean that running lights arent actually required by law? I mean if they are absolutely required by law,then why doesnt this adapter have a provision for it?

I purchased this adapter at Walmart,and it was the only one that would fit the style of plug on my factory receptacle on my truck.

Anyone think this is sort of hokey.What am I supposed to tell law enforcement when I get pulled over for no running lights on my trailer. Dont know if that will go over real well,but its plain as day if you look at the pics of the schematic on the receptacle cover on the truck and then look at the adapter plug. The adapter doesnt have provisions for running lights!!

The adapter plug:(pay attention to the top of the plug (slot) and orientate yourself with the receptacle cover to understand which terminals get power from what.)

Your adapter plug is correct when you pull it out and turn it arround to look at it left and right are reversed.  You want to start with simple things, check your ground, bulbs, and connections.  Make sure everything is clean, tight, and in good shape.  Check the lights if they still do not work get a test light and check power at the trailer lights where the bulbs plug in, if there is no power there un plug the trailer and check power at the adapter, if not there check the truck socket this will tell you where the problem is.  Contact cleaner and sand paper works well to clean the connections and Corrosion X or LPS 2 used regularly will help prevent more problems.

I had a similar problem.  All the lights on the truck worked, running, brake, 4 way flasher, and turn signals.

But one of them did not work on the trailer.  Changed bulbs, still did not work.  It appears your truck was factory wired for a trailer.  If so, it is possible that the trailer lights are on separate circuits, and fused separately.

Check your owners manual for the fuses.  If the trailer wiring is isolated from the trucks lighting, you should be able to see it in the owner's manual.  If you don't have the manual, pull the cover from the fuse box, there is probably a printed diagram indicating which fuse is for what. 

Look for trailer tail light.  That was the problem with my rig. 

I recently (like last week) found out that I have a similar problem as the OP with my trailer. I went all last season just thinking that the place that installed the trailer hitch had just wired it incorrectly. I didn't have the best experience with them so I really didn't want to take the truck back and wait even longer for the problem to be fixed, so I just didn't haul in the dark. However, this year I wanted the problem to be fixed. After checking all the wiring and lights (which are LED) I found out that the vehicle just doesn't come wired for constant power, the running lights. Appearently I need to get an upgraded tow package of some sort from the factory/dealership. Needless to say, I'm really upset that I will likely have to pay more money just to have running lights that work when all the other lights function perfectly. Other than just trying to make some extra money of you, why would they sell the vehicle this way? Has anyone else had this problem, and is there anyway I can go about solving this problem without purchasing an upgrade from the manufacturer? I drive a 2010 Nissan Xterra if that helps in any way.

choupique- You are totally correct about the adapter plug. Didnt look at it the way you did...Thanks for clearing that up.

Fishing Rhino- I took your advice and checked the fuses under the dash with the owners manual. There was nothing in the book about trailer lights.

I turned the page and it showed another fuse box under the hood,which did have a fuse for trailer lights.

Found it and removed it. Low and behold it was Blown.

Well now I have to get another fuse and hopefully that will correct the issue. Ive towed cars ALOT with this truck and have never had an issue with the trailer lights not working before.

Thanks for helping narrow down this issue!!!

I recently (like last week) found out that I have a similar problem as the OP with my trailer. I went all last season just thinking that the place that installed the trailer hitch had just wired it incorrectly. I didn't have the best experience with them so I really didn't want to take the truck back and wait even longer for the problem to be fixed, so I just didn't haul in the dark. However, this year I wanted the problem to be fixed. After checking all the wiring and lights (which are LED) I found out that the vehicle just doesn't come wired for constant power, the running lights. Appearently I need to get an upgraded tow package of some sort from the factory/dealership. Needless to say, I'm really upset that I will likely have to pay more money just to have running lights that work when all the other lights function perfectly. Other than just trying to make some extra money of you, why would they sell the vehicle this way? Has anyone else had this problem, and is there anyway I can go about solving this problem without purchasing an upgrade from the manufacturer? I drive a 2010 Nissan Xterra if that helps in any way.

It does seem odd that Nissan would do this, but you apparently heard correctly. This might help.

http://www.suspensionconnection.com/cgi-bin/suscon/T43605-xterra-wiring.html

Good call by Rhino with the fuse, I tell you to start with the simple things and forget to mention the fuse.

I recently (like last week) found out that I have a similar problem as the OP with my trailer. I went all last season just thinking that the place that installed the trailer hitch had just wired it incorrectly. I didn't have the best experience with them so I really didn't want to take the truck back and wait even longer for the problem to be fixed, so I just didn't haul in the dark. However, this year I wanted the problem to be fixed. After checking all the wiring and lights (which are LED) I found out that the vehicle just doesn't come wired for constant power, the running lights. Appearently I need to get an upgraded tow package of some sort from the factory/dealership. Needless to say, I'm really upset that I will likely have to pay more money just to have running lights that work when all the other lights function perfectly. Other than just trying to make some extra money of you, why would they sell the vehicle this way? Has anyone else had this problem, and is there anyway I can go about solving this problem without purchasing an upgrade from the manufacturer? I drive a 2010 Nissan Xterra if that helps in any way.

It does seem odd that Nissan would do this, but you apparently heard correctly. This might help.

http://www.suspensionconnection.com/cgi-bin/suscon/T43605-xterra-wiring.html

Thanks for the link.