Tow harness question

[LPC]

Hi I’m Leo and new to RVing
I have a 2016 thor fourwinds 26 a class c. No information came with the coach or Ford E 450 chassis so any help will be appreciated. I have no power to the 7 pin tow harness. I used a aux grounding point when checking it so I don’t think it’s a ground. Is there any fuses or breakers in the coach that would cause that. I checked under the hood fuses and they are good. Didn’t check under the dash but don’t think one fuse would kill all 7 pins.
Thx

[Casita Greg]

First thing I'd check would be to pop the hood on your truck and check your battery's POS (+) terminal for an extra black wire, (not the heavy wire,) and within a few inches of where it attaches to the battery there is usually an in-line fuse holder. Check the fuse, as it may be blown. If you have a self-resetting circuit breaker instead of an in-line fuse, it may be shot and needs to be replaced. Anyway, if you don't have any power on the downstream side of the black wire that feeds the 7-Pin Bargman trailer connector, that would be the first pace to start looking. If you have power near the battery, but not reading power inside the 7-Pin connector on the back of the truck, then your problem is in the wire between the two points, which needs to be checked for damage or being disconnected.

[floyd]

2016 is a bit early, but on my 2019 Ranger the TV has to sense the trailer hookup before it activates.
This involves something like starting the vehicle and stepping on the brake and I think it may even require shifting it once before it will start to run the charge line.

I was perplexed when my new truck would not work the trailer harness until I found that out. Since then it has just worked and I have forgotten the cycling sequence.
Your vehicle may not have such programming.

[Casita Greg]

That's true too. My wife's 2016 Chevy Silverado has an automatic shut-off to the trailer 7-Pin power outlet when the ignition is turned off, it kills power to the 7-Pin in order to prevent discharging the battery while the truck isn't running. With my old 2004 Nissan Frontier, you have to physically pull the plug out of it or it will drain your battery overnight.

[floyd]

Originally Posted by Casita Greg

That's true too. My wife's 2016 Chevy Silverado has an automatic shut-off to the trailer 7-Pin power outlet when the ignition is turned off, it kills power to the 7-Pin in order to prevent discharging the battery while the truck isn't running. With my old 2004 Nissan Frontier, you have to physically pull the plug out of it or it will drain your battery overnight.

Yes, I failed to mention that the charge line to the trailer is off when the ignition is off on the factory tow package, good point.