Cargo trailer issue
Thread Starter
Junior Member
Joined: Apr 2022
Posts: 6
Likes: 1
Cargo trailer issue
Hey all, new to this forum
I have a 2019 f150 and recently bought a cargo trailer. All the lights work except the inside ones. I installed new led in the trailer but still no go.
If I hook up a battery (from my rv) directly to the control box on the trailer they work fine. However when I hook up to my truck they don’t.
am I doing something wrong or what can I check??
I checked all fuses and everything is good.
When I use leads and plug into the trailer plug in, neg to the ground on the 7way plug and pos to the white which is the inside light wires they don’t work, but as mentioned when I hook up directly to the box on the trailer they do
any help is appreciated
tia
I have a 2019 f150 and recently bought a cargo trailer. All the lights work except the inside ones. I installed new led in the trailer but still no go.
If I hook up a battery (from my rv) directly to the control box on the trailer they work fine. However when I hook up to my truck they don’t.
am I doing something wrong or what can I check??
I checked all fuses and everything is good.
When I use leads and plug into the trailer plug in, neg to the ground on the 7way plug and pos to the white which is the inside light wires they don’t work, but as mentioned when I hook up directly to the box on the trailer they do
any help is appreciated
tia
Senior Member
Joined: Jan 2013
Posts: 608
Likes: 314
Use a volt meter to see what is hot to be sure it is wired correctly. Start at the 7 pin connector on the truck and work your way back. Once you verify power there, go to the next connection point of the hot wire inside whatever box device it goes to next. I'm not sure, but the truck may need to be running to put out power through the 7-pin connector. Ground is also important, so be sure to use a trailer ground as you go so you are validating that connection as well.
Thread Starter
Junior Member
Joined: Apr 2022
Posts: 6
Likes: 1
After some digging around i found out the my 2019 F150 don't have 12v coming out of the 7way plug in ,which is stupid.
Anyway, im wondering if there is some way (easy) to hook up the inside lights and make them work??? Without having to install relays and running wires in the truck?
I am thinking 1 of 3 things
1)can i tie into my side marker lights, then run it to a switch, then to the lights??
2) or if i switch the wires. Take the inside wire light wires and put them on the same post as the side marker lights????
3) can i hook onto my trailer battery for my electric brakes (neg to neg, pos to pos) then run to a switch inside then to m lights???
I know ill have the have the lights on the truck to the on position but for the amount of time they will be used it wont be much.
Just want some light in the trailer.
Anyway, im wondering if there is some way (easy) to hook up the inside lights and make them work??? Without having to install relays and running wires in the truck?
I am thinking 1 of 3 things
1)can i tie into my side marker lights, then run it to a switch, then to the lights??
2) or if i switch the wires. Take the inside wire light wires and put them on the same post as the side marker lights????
3) can i hook onto my trailer battery for my electric brakes (neg to neg, pos to pos) then run to a switch inside then to m lights???
I know ill have the have the lights on the truck to the on position but for the amount of time they will be used it wont be much.
Just want some light in the trailer.
Senior Member
Joined: Feb 2012
Posts: 3,770
Likes: 2,178
From: SE Michigan
Answered this in the other thread you started on the same topic:
https://www.f150forum.com/f2/cargo-t...1/#post7188410
(You only need to post things once) 😉
https://www.f150forum.com/f2/cargo-t...1/#post7188410
(You only need to post things once) 😉