2017 F150. I purchased an electric trailer jack with a pre-installed 7 pin plug. When I plugged it into the 7 pin connector the jack would not work, even though I have lights when my trailer is plugged in. (You can plug the trailer in or the jack) I took the jack back to the store and they suggested that I test it on one of their trucks just to make sure. The jack worked..... so I bought a tester and found out I was not getting 12V power to the connector on my truck.

After doing some research I found out that the truck can tell if there is a trailer plugged in and therefore will send power to the connector if there is. When I plug the trailer in I get a message on the dash indicating "Trailer Connected". When I plug the jack in, I get no message. This is more indication that there is no 12V power to the connector.

I've looked to see if I need a special relay and/or fuse but I do not see specifically in the owner's manual where they would go.

Any help would be greatly appreciated.

 

Welcome to the site..

Ford vehicles equipped with a factory trailer brake controller utilize a trailer module (TRM) which initiates the trailer 12V charging system as you stated.

For trailer charging circuit to operate, the TRM must detect a trailer is connected and a brake pedal input before charging power will be present at the trailer connector. You might try the jack with brakes applied to see if the jack would create enough resistance to trigger the flow..

 

Thank you Hayapower -
I think I tried that but will try again. Is there a way around that? Having to connect the trailer jack then press the brake pedal, then go back to the trailer jack is excessive.

 

You could add in a switched stand alone circuit to the back, which depending on the jacks total amp draw (?) may be better for the TRM.
Or you could use a 7 way ‘Y’ splitter and a trailer emulator inserted in one leg . With the emulator installed, the second available pigtail connector should be active..