I took delivery last week on a 2020 F250 Lariart with the factory 5th wheel prep and trailer plug in the bed and bumper. Is there a separate pin in the plug with a 12v charging wire as it is not labeled that way?

 

On a 7 pin round trailer connected the charging wire is pin 5.
What makes you believe that yours is not working?
Do the brakes and all the lights work?

 

Thank you for great info. I will tow first time today. So does that mean running lights must be on to have 12v charging trailer battery?

 

[QUOTE=Kenny White;120767]I took delivery last week on a 2020 F250 Lariart with the factory 5th wheel prep and trailer plug in the bed and bumper. Is there a separate pin in the plug with a 12v charging wire as it is not labeled that way?[/

 

Thank you for great info. I will tow first time today. Do running lights have to be on to have 12v charging the trailer battery

 

I do not know 100% but I would pretty safely assume the trailer battery should charge the entire the time engine is running regardless of anything else.