I pull a cargo trailer for work. I have an exhaust fan mounted in the roof to vent heat that I always leave on so when I start the truck it turns on. I have noticed on my 2023 truck that it does not always automatically come on. Sometimes I have to push the power button on the fan to power off then on for the fan to start. It seems as if that is when power is sent to the trailer for use.

Can someone tell me what may be the issue? I am going to install a battery in the trailer and would like to have it charge from the truck.

Thanks,
klirette

 

there is a certain combination of turning on the truck, opening the door, keys inside with trailer connected that turns on the power to the 7 pin.

 

Just run a dedicated circuit from the battery back to the rear bumper and make a connection for your fan only...save a lot of fooling around.

 

If klirette were to run a direct line from battery with a connection to the trailer for the fan as you suggest the fan would have to be manually turned off then on. It seems the trailer remains hooked up over night. klirette does not want to have to turn the fan off then back on manually. klirette is wondering why the truck doesn't supply power under load when the truck starts. klirette states that the fan must be turned off then back on for the truck to supply power if the trailer remains hooked up and the fan is on.

I wish I could give you an answer to that klirette.

 

Suppose you could use the bed outlet, plus a battery charger and a wire to power the trailer. A bit of a hack, but it would work

 

It’s interesting to me that there has been no definitive answer to the “trailer not charging” issue many have experienced. As I’ve said elsewhere in this forum, on my ‘25 Lariat PB, I have to start the truck and shut the door BEFORE plugging in the trailer (or unplugging and plugging back in if the trailer has already been connected, say at a rest stop or gas station) EVERY time the truck has been turned off in order to get the trailer charging circuit activated.

 

I don't have that problem with mine. Typically the truck is running and doors open when I attach my trailer. As soon as I plug in, the trailer lights up. Do nothing special at stops and everything works as expected.

 

Ok still having this issue. I have installed a battery into my trailer and it was working fine. Although I don’t believe that my battery is getting charged. I saw a message on my dash screen that said “ Trailer Battery not Charging. See Manual”. What does that mean? Am I not getting 12 volts to my trailer? I just want a constant 12 volts delivered to the 7 pin plug at all times the truck is running. Is that too much to ask.
Any help with this issue would be appreciated .

Thanks,
klirette

 

go into the trailer settings on your dash options and set up the trailer you're towing (brake type, etc). Give it a name and save it. The "smart" trailer controllers that showed up in 2015 have a bunch of requirements before sending power and if you set it up it'll connect that configuration each time. It needs to see some resistance or voltage on the 12V line before linking it to the electrical system on the truck. Brake wire also needs to see somewhere between 2 and 20 ohm so it can sense that there are actually brake magnets there.

 

‘25 PB. I have my trailer set up in the Truck. My trailer has a Redarc controller that may be confusing the truck because, as I described above, the only way I can get the trailer to charge is to start the truck, close driver door, and THEN connect the 7-pin. Nothing else works. PITA whenever I stop for gas or pee stop or whatever.