[loufish]

Should be fuse #32, 10 amps....I've attached a wiring diagram...(on Fig. 2)

 

[BCBowers]

Thank you!

 

[humblerb]

If yours is like my 05 Titan or 11 Armada, when you are looking in the rear fuse box, there is a panel that looks like it is the back of the box. It sets up rather than lays down. It is actually a panel that comes out. It has clips on the side similar to the top.
Once out, you can pinpoint the exact fuse and check without even removing if you have a simple tester.
I had the same issue with my Armada and the bad fuse was on that panel.

 

[orionS14]

If you haven;t found the dead fuse already, here's the one that popped when I had no running lights on my trailer:

(pic inside --> )
http://www.titantalk.com/forums/tit...no-running-lights-my-trailer.html#post2131839

- Brian

 

[BCBowers]

Yep that's the one it was... do our trucks have spare fuses in the fuse block? Luckily my Corvette does so I was able to grab a spare 10 off of it and swap.

 

[AK_White]

I have a 2015 Armada that came without the tow package. I installed the hitch and electronic brake controller to tow my 30ft travel trailer. I recently just bought an enclosed trailer with a 4 way harness that I just put new LED lights on the back of. When I finished the install I tested the running lights, brake lights, and blinkers and all of them worked. I noticed that the side marker lights weren't hooked up so i popped off the lenses and connected them. I didn't test them after that because I figured everything was good to go. The next morning i noticed that the only lights that worked were the brake lights and the blinkers. After reading through this thread I tried swapping the blinker relays with the one under my dash (all checked good), I checked all of the fuses and found F4 was blown (it was a 10amp so I changed it out) on the part of the fuse box under the hood that appears to be standing upright. Still no running lights. I then ran an external wire with just my new tail lights hooked up (not my side marker lights) and they still don't turn on. I verified that the lights are good by running the constant wire to the blinker and there is no issue with either light. I have all 3 relays under the hood (2 blue 1 brown) and the blue relay under that dash. The only relay I haven't tried replacing is the brown one.

 

[Lawmanphil]

I had a similar issue. I replaced all of the fuses and relays I could find and was mentioned on here. (Thanks for the help). It was a hidden 10amp fuse at the very bottom row of the back fuse box. It was in slot F-4. It fixed my running light issue.