trailer lights inop

[kforrest]

I recently blew a tire on my 5th wheel, which destroyed the fender and broke loose the wiring to the marker light on that fender.  A familiar story, I'm sure.  I replaced the fender and light, but now I have no tail lights or marker/running lights on the trailer.  I also noticed that the marker lights on the truck mirrors are not working.  I think they (the mirror lights) should work anytime the headlights on the truck are on, and correspondingly, the marker and tail lights on the trailer should work.  I suspect I have a grounding problem, but don't know where to start.  I have a 2008 Ford F250 6.4L diesel and a 1996 Alpenlite 5th wheel.

 

[Rene T]

Check the fuses on the truck for the tail lights and running lights. You probably blew a fuse when the wire broke.

 

[grashley]

Try Rene's idea first!

Do truck tail lights / running lights / side marker lights work?  Any difference whether the FW is plugged in or not?

Was any wiring damaged by the flat?

Run a LONG ground wire from a non function light to a known good ground.  Does it work now?

The umbilical cord that plugs into the truck should go to an electrical box on the pin box.  Start there and check continuity.  With running lights on, is there power there?  If yes, work your way back.