F150 2013 3.5 l ecoboost engine. i cannot get my truck to charge my trailer batteries while towing. fuse and relay are in place. what next?

 

Dennis, you have to have your trailer hooked up to the 7-blade plug at the back of your truck to get battery charging. Is that the one you are using? If so, and it seems there's no charging current, use a multimeter to see if there is charging voltage at the plug. If there is, the problem is in your trailer. If no charging voltage at the plug with the ignition ON, you have a wiring fault in your truck somewhere.

- Jack

 

Thanks Jack for the info. i have no current to the plug on the truck and verified the trailer wiring is correct. i will begin working my way back up towards the engine looking for some current somewhere. I will also swap out the relay to see if it could be bad, the fuse tests out fine.
dennis

 

For what it's worth, I discovered after one camping trip that I had no battery charging current either. When I pulled the relay, I discovered one of the pins had been bent so that it went into a "center" slot. The two pins were supposed to go into the two "outside" slots.

I honestly don't know how it got this way. I was the one who installed the relay and I know I did not bend that pin. And, I had charging current when I first installed it. I can't help but think someone at the dealership did it when I had the truck in for an oil change. I am suspicious they were trying to drum up business?

Anyway, check your relay's pins. They should ALL be straight.

- Jack