7 pin plug power?

**Najataagihe** · 05-08-2019, 09:30 AM

Originally Posted by Country Campers

Well I do not mean to be , whatever the word I am looking for , but that is one of the strangest (or dumbest) things I have ever heard.

Brian

Not really.

When you are setting up in the rain, you are often soaking wet.

You hop out of the truck and, without thinking, reach over and disconnect that cable while standing on wet ground.

Hello, Ben Franklin!

Having full current to that 7-pin connector is not a good idea anytime there is "wet" around.

Blown fuse, if you are lucky, "ZAP", if you are not.

"I" usually close the door when it is raining, but it would be interesting to see if it cuts the power when the door opens and does not re-energize until you are in the seat and push the brake pedal.

If that is the case, it is a delightful little safety feature of which most folks would not be aware (including me).

I rather like the idea.

**cfowler55** · 05-08-2019, 10:13 AM

Originally Posted by Najataagihe

Not really.

When you are setting up in the rain, you are often soaking wet.

You hop out of the truck and, without thinking, reach over and disconnect that cable while standing on wet ground.

Hello, Ben Franklin!

Having full current to that 7-pin connector is not a good idea anytime there is "wet" around.

Blown fuse, if you are lucky, "ZAP", if you are not.

"I" usually close the door when it is raining, but it would be interesting to see if it cuts the power when the door opens and does not re-energize until you are in the seat and push the brake pedal.

If that is the case, it is a delightful little safety feature of which most folks would not be aware (including me).

I rather like the idea.

Pretty sure DC current will not follow a liquid. That is what allows vehicles to have in-tank pumps with open connectors submersed in fuel.

**Airrace** · 05-08-2019, 04:44 PM

Well finally after a short 2 week trip and a couple of long days under the trailer figuring out how I got a 12 tooth pinion gear here is what happened on my 2018 F-350. Power off-nada anywhere. Open door, reach in and start truck (standing outside), door open, power to the trailer hot wire with no plug. I have a Lariat. Maybe the Platinum and Limited have more "smart" features that cause you to push the brake, close the door. Not sure. Have worked around 12 volts for 50= years and never been shocked when wet. Been burned by 12 volts and been shocked by 20k volts from coil (try reaching under the header on a 396 (chev) and grab the plug wire when running. Yup, back and forth about 4 times before I could get away

. Be fun to check into if this is model specific

**Najataagihe** · 05-09-2019, 06:34 AM

Originally Posted by cfowler55

Pretty sure DC current will not follow a liquid. That is what allows vehicles to have in-tank pumps with open connectors submersed in fuel.

That depends upon the liquid.

Pure water: No, no ions, perfect insulator.

Water/acid mix: Add dissimilar metals and, voilá - Battery!

Gasoline: Most mixtures, too much resistance for 12V.

Diesel: No, WAY too much resistance for 12V.

Water with ionized contaminants (most lake water): Yes, we have a winner, depending on the contaminants.

It's not the water that gets you, it is the stuff dissolved in the water.

Rain water is DIRTY and it is quite possible to push even a lousy 12V through it, especially if you are in mud.

Originally Posted by Airrace

Have worked around 12 volts for 50= years and never been shocked when wet. Been burned by 12 volts...

I have gotten bitten a couple of times by 12V when the shop floor was wet.

Rubber soles on my shoes stopped that problem.

I had to resuscitate one of my soldiers whose heart stopped when he got lit up by a 24VDC (NOT 12V) circuit while working on a vehicle in wet grass.

It can happen.

Why risk it?

...and been shocked by 20k volts from coil (try reaching under the header on a 396 (chev) and grab the plug wire when running.

OUCH!

That hurts just thinking about it.

**Steven@147** · 05-09-2019, 09:42 AM

Listening (reading) to the Ford owners, I am sure there is a method to their madness. Seems like manufacturers are putting all sorts of safety devices on things (lawn mowers come to mind), probably for liability reasons.

But you all got me curious on how my 2018 Ram works (see truck details in sig line). There is 12.3VDC on 7way pin 4 all the time, bumper plug and bed plug, trailer cord not plugged in, just setting there in the driveway not running, door open or closed, tail gate open or closed it does not matter, there is always 12.3VDC on pin 4 both 7 way plugs. Start the truck and the voltage goes to 14.3VDC on pin4 on both 7way plugs. The truck 7way bumper plug is up higher than the bumper, the 4 pin boat or small trailer (no electric brakes) connector is much lower under the bumper.

Not saying its right or better, just the way it is. Now I am sure if you left the trailer cord plugged into the truck 7 way for a long enough time, engine stopped, it would drain the truck batteries down. But if that happened then that would be my fault.
Now I am not sure what truck ckt protections are in place if the trailer cord is plugged into the truck 7way and RV shore power is connect and energized. Seems like you would have two 14VDC charging sources feeding the RV battery at the same time. Probably not, Anyway I am not concerned, I never plug the trailer cord into the truck 7way until shore power has been removed from the RV.

There is 14VDC on trailer cord pin 4 with shore power connected and energized.

**Country Campers** · 05-09-2019, 09:56 AM

Steve

My Chevrolet is exactly like your Dodge , power all the time. I would be nice if power was only there when engine is running.

Brian

**kevinpo** · 05-09-2019, 10:14 AM

Steve,
Now you've got me wondering? My truck stays hooked to the camper all the time I'm camping or sometimes 4 or 5 days in the driveway before leaving for camp. I will have to disconnect the camper batteries and see what's powered with the truck off.

Regards,
Kevin

**Steven@147** · 05-09-2019, 10:57 AM

Well it maybe you Ford guys are better off. Only energize pin 4 with the engine running or once you step on the brake pedal. That kind of means your actively towing and shore power is not connected. Or de-energize pin 4 once you open the drivers door, kind of means your unhooking and going over to shore power. Kind of reduces the chances of have two separate charging ckts active at the same time on the RV battery or the truck battery.

But we can't forget RVs are not the only thing that gets towed. My car trailer, its nice to have the 12 VDC or 14 engine running, on pin 4 all the time to help run the winch. Of course there is no converter charging the car trailer battery in just a normal 20 foot car trailer.

Or too if you're stopped over night or boondocking short time, its kind of nice having the truck battery to supplement the RV battery to keep from running one or the other down.
On the other hand towing a TT where the dealership ran the battery flat and you can't operate the hitch jack, and your way out in the parking lot. It was nice to have that 12-14VDC on pin 4 to get the Imagine jack up and trailer hitched to the truck. Silly dealership!

LOL!! I guess we just have to learn to deal with whatever we got!