Does 2011 f250 have to be connected to trailer for trailer battery charge to work. Is there some option to turn it on in the menu driven system. Fuses have all been checked (#90 in the BJB and #55 which apparently powers the tow charge relay #102) Tow charge relay has not been checked as I do not know how to pull it. Any help would be greatly appreciated.

 

Welcome to the site..

The battery charge should be active any time the key is in Start/Run.
55/10 protecting the switched relay function, 90/25 is protection load side of the relay.

 

I appreciate the help, however with the key in the start run position I have no 12v on the trailer charge wire so I am still in trouble. If no one else has anything to offer I guess it is off to the local dealer for a relay and possibly a tool to pull the old one.

 

Back from dealer with new relay (102) and new fuse (90). Replaced both still no 12V on the trailer charge wire. Now I know that my truck detects when a trailer is connected, as when I first connect a trailer and start up it displays a "trailer connected" message when connected to a trailer, and then shows what the trailer brake gain is set to. Maybe it also turns on the power to the trailer charge wire? So I guess it is off to the lake tomorrow to hook up to the trailer and see if it works.

 

Found problem. Connector behind rear bumper seems to have a nasty habit of going open on the trailer charge wire. It looks like with normal everyday use water and snow, road salt, mud and what not, gets splashed up and on the connector making for a very inhospitable place for an electrical connection. Solution was to take connector apart and clean and refresh the connectors contacts. Once this was done power was once more available on the in bed trailer connector as well as the bumper trailer connector. Probably won't be a permanent fix, so will have to keep an eye on it each season.