Trailer Lights

[Kylesmith3021]

So first time this has ever happend to me...Brake lights and signal lights and r ways work on travel trailer however no running lights work on it...Truck lights are all working fine..I tried truck lights on auto then aux on and still no running trailer lights..I tow with a 2014 f150 ecoboost with a 7way plug..Not sure what to do since i am not savy with electrical things

[Community Alumni]

If your trailer is equipped with the typical metal junction box with wirenuts on the connections then you may want to upgrade to something like this. The connections are more secure and the box is also more weatherproof.

Link

[Kylesmith3021]

pulled the cover for the junction box and noticed rate away a wire came undone from all the wires for the lights..reconnected and all lights and running lights work

[wnjj]

Have you pulled the plastic hood off the 7-way plug on the trailer to see if a wire came loose from a terminal?

[Kylesmith3021]

Just checked with a friend that stopped over and it did not work with his 7way so this confirms that its the camper side...I checked all fuses inside and out but nothing was blown..I guess i will uncover the junction box on the outside and go from there

[rbpru]

One of the receptacle terminals on the TT 7 pin plug is supposed to power the running lights.

One of the receptacles on the TT 7 pin plug is supposed to come from the battery.

According to the latest issue of Trailer Life magazine, if you jump the 12 volt receptacle terminal to the running light receptacle terminal with a fused jumper wire, the lights should light. If the circuit is open they will not light. If the circuit is shorted it will blow the jumper wire fuse.

A fused wire jumper can be purchase at the auto parts store.

If this is too complicated, sometime it is easier, though more expensive, to let the pros do it.

[Kylesmith3021]

So i changed out the 7 way/4 way on my truck hoping this was the issue but still no running lights on the camper..I am completely baffled on what is causing this.

[mike-s]

So, maybe you need one of these, too.

[Kylesmith3021]

so the harness part is right for truck end but i need it to be wires on other bc i had a aftermarket hitch and 7 way put on my truck bc it didnt come with it

[Lynnmor]

mike-s wrote:
That's the trailer side wiring. His problem is on the vehicle side. Depending on where the wires are damaged, this might be what he needs.

Sorry, I didn't understand. I think you got it right.

[mike-s]

That's the trailer side wiring. His problem is on the vehicle side. Depending on where the wires are damaged, this might be what he needs.

[Kylesmith3021]

its not that part its a actual plug in harness to factory plug then you wire those wires to the 7 way wires..unfortunetly theres not enough wire from harness to re wire

[Lynnmor]

Kylesmith3021 wrote:
so i found where the problem was but im not sure what to order...its a harness piece that plugs into truck under the bed by spare tire and goes to my 7 way for my truck...I noticed it has a couple of wires chewed up

Available at many auto parts stores and trailer supply stores.

Like this

[Kylesmith3021]

so i found where the problem was but im not sure what to order...its a harness piece that plugs into truck under the bed by spare tire and goes to my 7 way for my truck...I noticed it has a couple of wires chewed up

[westend]

Kylesmith3021 wrote:
i pulled the fuses under the hood and checked them but nothing was blown

Do you have a main fuse panel inside the truck? I'd suggest to break out the owner's manual and find where the fuse is for the trailer lights. That fuse, in my truck, is located in the main fuse panel beneath the dash. Yours may be in the kick panel or under the dash.

If this is all too much for you, seek technical help.

Looked it up: The fuse block is under the glove box, passenger side.