Any trailer wiring gurus in the house??

[3rdShot]

2012 F150 Lariat Limited…all running lights / headlights / signals & brake lights on the truck work.

16’ Centex Trailer, dual axle… running lights work on both sides, left brake and signal lights work, right side brake & signal lights are not working. Bulb is fine, I swapped with the left bulb, bulb works as it should. I’m assuming the green wire is the the signal & brake wire…no apparent breaks in any of the wiring. I’ve unbolted and sandpapered the trailer ground wire and bolted it back down, and unbolted the right blinker assembly and sandpapered the area the holder bolts / nuts contact so should have good ground, as the running lights work on both sides, but the right side signal & brake light is still not working.

Any thoughts? Is there a specific fuse only for the right trailer signal & brake that may be blown? I don’t have the owners manual.

Have hit the limit of my basic trailer light knowledge, so any suggestions are welcome…

[Bard]

Small fuses under the hood,control your trailer lights. They blow often.

[rolylane6]

Here's a link to your manual.

2012-f150.pdf - Dealer E Process https://cdn.dealereprocess.org/cdn/s.../2012-f150.pdf

Fuses start on page 336
It looks like number 38 under the hood for the right side

[rwurz]

Maybe use a test light at the light connection on the trailer while some one is pushing the brakes. If nothing there check at the plug on the truck side.

[critter69]

Maybe use a test light at the light connection on the trailer while some one is pushing the brakes. If nothing there check at the plug on the truck side.

This right here is where you want to start.

[Quackerbox]

Probably one of those POS crimp fitting things under the trailer.

Check power at the light with a meter or test light

[Drycreek3189]

Small tip, do not leave your automatic type light switch on while hooking up your four point flat trailer plug. It’s too easy to short your lights out and you may not even know it.

[brushtrooper]

check the fuses. Many times Ford did not include all fuses needed for trailer lights

[flywise]

I had the same problem yesterday. The ground on thst specific light was not making a good connection

[91cavgt]

I had the same problem yesterday. The ground on thst specific light was not making a good connection

I had the same problem on my little cargo trailer. A year before I had replaced all of the wiring. Had power at all of the electrical connections. A rusted ground was my problem. I used a sewing needle soldered to a wire that was clamped to a ground to pierce the insulation on the ground wire by the light, and the light started working. Traced the wires back, found the bad ground, fixed it and the lights work great.

[Paycheck]

Sounds like that fuse to me that Rolylane mentioned.

[M16]

Another little tip. Change your lights from bulbs to led.

[Big_gun]

Didnt some of the fords used to have a different trailer connector ? We used to have to carry a Ford one and a GM one.

[Strummer]

Have you check for power on your plug ? My issue was with a bad wire before my plug on the truck .

[PYBUCK]

Use a test light at the lights. If you have power there, it is your ground. You can run an independent ground wire to the lights that are not working to verify if it is the ground at the light the is bad.