Hey folks! I love this truck! She pulls my trailer like a dream. We hooked up some bed lights this weekend with the intention of using the 12v hot and ground off the 7PIN. Slight issue. Even though the fuses are all there and the manual says it should be hot there is no 12v on the 7 PIN. The dealership checked everything and says everything is at it should be, Now we checked a 2016 XLT and a 2017 Platinum FX4. Both have the same issue. The 7 pin has no 12v hot. A quick Google gets a hit on etrailer.com and says to populate position 27 up under the hood however this truck only has one pin in that slot so this port is not used with the features of my truck according to Ford. Any ideas?

 

The BCM will only provide power to the +12V wire after a depression of the truck brake pedal and the truck detects load from the brake lights of the Trailer. This is by design, and I have personally confirmed to be the case with my trailer.

In short, your not going to be able to use the 12v trailer source for your lighting - find another power source.

 

Ya we did. A line right to the battery did the trick and we used the ground off the 7 PIN. Brought up the question of overhead lights in a trailer powered by the tow vehicle or say a power trailer jack. Both of those use the 12v hot off the 7 pin. I will test this later today.


Thanks!

 

Any trailer accessories will work fine, as you will have the 7pin connected to the truck- have pressed the brakes, and the BCM will have supplied power through the 12v+ line.

 

The problem is, when you take your foot off the brake, you loose 12v again unless you are in drive. If you're in park, the charge line is only active with your foot on the brake essentially making it useless for interior lighting or accessories.

 

True for say a trailer jack since all of that gets done by default when hooking up to the trailer. But for something like a dome light inside the trailer powered by the 7 pin, not so much. My guess is it times out to preserver battery on the tow vehicle. I am going to test this later today. Still surprised the dealership did not know this.

 

So...... if in drive there IS 12v? If that's the case, I can use the 12v to help keep my trailer batteries charged (with a diode in place of course).

 

Seems to be a lot of confusion on this. The line provides 12V+ in park too, AFTER you have touched the brake, and the truck has detected the trailer.

I have verified using my Trimetric 1030 in my RV that I am receiving a charge at idle....

 

There's no confusion on mine. If in park, there is only 12v with your foot on the brake. Remove your foot and it goes off. In drive it stays on all the time after the initial depression of the brake pedal...

 

Yes, once in drive, 12v stays active.

 

Interesting, we have eaten a few dinners in the Rig after pulling off with the truck idling out front definitely charging after the sun is gone down (solar is inactive)...your monitoring through a Trimetic or similar?

 

No, I simply checked with my snowmobile trailer's interior lights. In park you need your foot on the brake to activate the line and the make the lights work. Take your foot off and the lights go out. Put it in drive and the lights are on no matter the condition of the brake pedal.

 

I don't believe the test light will provide the load required to have the BCM turn on the 12+ line.

I can see the charge coming in from the truck a 3 digit amp meter pulling off a shunt between my RV and its batteries (notice the AMPS option), and the "Charging" light. There is no question.



TriMetric Model Descriptions - Bogart Engineering

 

I edited my post... see above. I didn't use my test light. I used my trailer. It was a while ago and I forgot... but it came back to me right after clicking submit... Trust me, I've got no power when in park with my foot off the brake. Yours may be different. Stranger things have happened.

 

Come to think of it, that's how I noticed it. I had to change my accessory lights over to my parking/running light circuit from the charge line so I could use them when the truck's in park and I'm not in it. I knew that I knew. I just didn't remember how I knew... LOL.