11screw50

So does your foot have to be on the brake when you start the truck or does the 12v activate once you push the brake pedal with the truck running? (still haven't even put the battery back on my trailer yet, maybe this weekend...)

subpay

Second Option, trailer hooked up, plugged in, truck running in park and apply the brake. I found this all out after accusing the dealer of not installing my fuses and relays. While standing at the parts counter I did a search on my phone and found the answer on another forum searching for "F150 battery breaker relay". It was a 2015 post.

Boulevard

I do not know which connector you are using but I do not think that the flat connector will charge a battery where the round one will.

I had this same problem and even though I have the trailer package the fuse and relay that allows power to flow to the trailer were not installed. To fix it I stole the relay from the passenger power seat circuit (an option that I do not have) and the fuse from the rear window defog (another option that I do not have) and viola! it works. I may have gotten them the wrong way around but basically I stole parts from circuits that I was not using and put them where I needed them.

I have never done anything special in order to 'activate' the 12 volt to the trailer. I just plug it in and it works.

swilky2000

Battery charging of TT from TV must have 7 pin connected and relay 9 and fuse 21 installed in engine compt. box.
Normally left in glove box when new.

part number
AL3T-15A416-AA

Ricktwuhk

As noted in the thread, for the newest models you must step on the brake pedal to activate the 12 volt circuit.

Steve Osborne

I hate it....just letting ford know.......dumbest move yet for tow package....