When towing, how does Truck power get to battery?

[Oregon RR]

2011 Desert Fox 21-SW.

Trying to understand how my trailer works.......appreciate any help.

So where is the 12-volt power lead from my truck's 7-pole trailer cord going into the trailer and then feeding back to my batteries? There is no wire dedicated to tow vehicle power going back into the battery. I've got pos and neg from charger/converter, a pos and neg from solar charger and a pos and neg to starter on my generator.

I know the tow vehicle will recharge my battery, but I don't know where the power goes to get there? Distribution panel? Charger/converter?

[R.Wold]

Terminal 4. Measure it there and make sure it’s hot (many new vehicles left this dead). If it is, check your 12v panel in the trailer with the truck plugged in and running. If you don’t have 13.7 or so, it’s not included in your trailer wiring harnesses. But at least you’ll have a good starting point to finish the job.

[Oregon RR]

wold -

Thank you for the reply, but where does the truck hot lead connect into my charging system to bring up the batteries? I know where it exits the truck.
That is my question.

RR

[450Donn]

If you trace the wire you most likely find the trailer side of the of the plug the wire connects sirectly to the house battery.

[Oregon RR]

Nope,

There are only 6-wires going into the batteries. 2 for solar, 2 from charger/converter and two to the onan generator starter.

So I'm thinking it is coming in via the charger/converter circuit? I put the solar in after I bought the trailer and it wouldn't be coming off the generator starter wiring.

[aether_one]

Originally Posted by Oregon RR

wold -

Thank you for the reply, but where does the truck hot lead connect into my charging system to bring up the batteries? I know where it exits the truck.
That is my question.

RR

Depends on which truck you have. Most pre-wired tucks require you install a 30 amp fuse in the correct location in the fuse box, it is not installed from the factory. Same for the trailer brakes main power.

[450Donn]

Originally Posted by tfryman

Depends on which truck you have. Most pre-wired tucks require you install a 30 amp fuse in the correct location in the fuse box, it is not installed from the factory. Same for the trailer brakes main power.

Thats only a GM thing, and not what the OP is aakong about. If the OP were to look under the street side near the front he most likely would see a jumble of wires. This is where the pig tail connects to the trailers wiring. This is also where the power from the TV is joined to the power from the battery and feeds to the fuse panel.

[Oregon RR]

Originally Posted by tfryman

Depends on which truck you have. Most pre-wired tucks require you install a 30 amp fuse in the correct location in the fuse box, it is not installed from the factory. Same for the trailer brakes main power.

I know the truck powers / charges the battery while towing - everything works just fine.

I just want to know why it works via the electrical system and what path the truck charge follows on the way to the batteries.

[Oregon RR]

Originally Posted by 450Donn

Thats only a GM thing, and not what the OP is aakong about. If the OP were to look under the street side near the front he most likely would see a jumble of wires. This is where the pig tail connects to the trailers wiring. This is also where the power from the TV is joined to the power from the battery and feeds to the fuse panel.

So then would tow vehicle power be coming back to the trailer battery via the converter/charger cables even if the generator is not running the charger?

[twinboat]

If you open up under the bottom cover of the trailer, near the tongue, you will probably find a auto reset breaker, tied into one of the wires going to the battery.

[R.Wold]

Originally Posted by twinboat

If you open up under the bottom cover of the trailer, near the tongue, you will probably find a auto reset breaker, tied into one of the wires going to the battery.

Or it was never connected. I bought a nice high-end horse trailer new and had to wire truck power to the batteries myself. I’d open up the 12v (Fuse) panel In the trailer and start tracing things back and you'll find out what’s going on.

[Oregon RR]

Ok, since this is the Northwoods area, I thought someone might know how it works.

Thanks for the responses.

[Bill111]

Northwood does this:

Under the floor, behind the hitch, under the trailer, there's a recessed area with a cover on it. The Umbilical cord from the truck connects to some circuit breakers and what not. That's where the batteries from the trailer connect too. Another set of wires goes from the circuit breakers to the DC distribution panel in the RV

[Bill111]

Originally Posted by Oregon RR

So then would tow vehicle power be coming back to the trailer battery via the converter/charger cables even if the generator is not running the charger?

No, the tow vehicle charge goes straight to the batteries. See my post above.