Hello,
I have a 2018 Ford F-150 and recently purchased a new NEO Cargo trailer that has two interior lights. When the trailer is hooked up, all of the exterior lights work, but the interior lights do not work. I've read on previous threads that I may need to add a fuse / relay, but I haven't come across which fuse and relay need to be added. I've checked the manual and called a couple dealers, but they don't seem to be aware of what needs to be done to correct the issue. The trailer dealer said this was common with F-150's. Wondering if anyone has had this issue with the recent model year F-150's and corrected it?

Thank you.

 

Have you added the trailer in your towing screen? That circuit might not power until it's added.

 

Is it a 4 pin or a 7 pin? If 4 pin, the cargo lights work off the running light circuit, if 7 pin then they work of the +12v, and you need to set the trailer up for that to activate.

 

Box trailer we bought had same issue wiring was not connected to the 12 volt that ran running lights, this was with a 4 pin connector.

 

There is a fuse and a relay in the fuse box under the hood that you need to add to activate the "charging circuit" for the 7 pin connector. It is the same stuff that you get when you buy the break controller kit from the dealer.

 

Thanks for the replies everyone. I'd like to try the fuse and relay first if possible to see if that corrects it. Do you know which fuse and relay slot I'm supposed to add to in the fuse box as well as what sizes they should be?

 

should be right in the owners manual, trailer battery charge fuse and relay is what they should be labeled as. and if your
truck came with factory trailer tow the fuse and relay should be in the truck somewhere, door pocket, glove box, under rear
seat etc. in a bag with instructions.

 

C'mon man you can't be spoonfed everything lol. Pull out your manual and it literally shows a pic where the relay goes. A nice diagram of the fuse box along with a pretty spreadsheet saying what each fuse/relay is for... and they even have fuse values!

 

It was common a few years ago but i don't believe it applies any longer, maybe if your truck has zero tow packages it may not have the relay in place. Have you verified that the lights are even wired, or done correctly? Their goal is to get as many trailers built per day as possible throwing aside quality so i wouldn't be surprised if they were missed.

 

Just went through the same issue with the brand new NEO trailer i picked up last week.
If your truck is 2015 or newer and has a trailer towing package, the trailer connector is know as "smart connector"
The truck will know when the trailer is connected and will send voltage to the proper pin to turn on interior trailer lights and charge a breakaway battery if your trailer has one.
It's a very simple process.
Hook up your truck to your trailer with the truck NOT running.
Start your truck and hold your foot on the brake pedal for 3 seconds, you will see a "trailer connected" message in your dash. You should now have power to the pin that will supply the 12 vdc to allow you to turn on your interior trailer lights and charge your breakaway battery....if you have one.
The owners manual is very poor at describing this procedure.........very frustrating.
Please try this and let me know.
Thanks.
rob