7-pin Connection Question

IN a properly set up tow vehicle there is an isolator, either a diode type or a solenoid type.

The bottom line is... Should not be necessary to unplug.

Second:...... When plugged in to shore power

I would not care if the RV fed power back to the TOW vehicles battery, With a good 3-stage converter in the trailer (Assumes you have one) the WORST thing that would happen is come the morning when you go to move on.. Nice FULL tow vehicle battery cranks her right up.

IN FACT.. Though I live in a motor home not a trailer.. both MH and towed care are rigged so if I do not plan on driving the car till Sunday, and today is Monday, I can plug the two 12 volt systems in together and ... Keep the car charged (Connectors provide many services,, One of the two on the motor home recently powered the flag-pole light for the patriotic holiday).

I appreciate all the input. It's no big deal to unplug so I'll keep doing what I've been doing with the thought that if I forget, it probably won't hurt anything in the truck. Thanks.

My Dodge disconnects as well.

My Ford disconnects when the engine is off. :)

I always unplug now. I didn't use to but a couple of years ago I left it plugged in on our way south. In the morning the truck wouldn't start. I found that the converter had failed and all my batteries were low.

I think Fords disconnect the charge line when not running. GM doesn't, not sure about Dodge.

Unless you have an older TV I doubt the 12v. charge line from the truck would be hot without the TV running. I know it's that way on my 15 year old Ford p/u with the factory tow package.

I installed an isolator solenoid in my charge line of my truck with this problem in mind.

If I am plugged into shore power, the truck is unplugged. When on shore power the process is reversed and the RV charger is supplying 12v back through the umbilical cord. IMO the 12v that is being supplied is not that clean or regulated and I don't like the idea of feeding it to the TV with all the computers these days.
If I am not on shore power and overnighting in a truck stop...the umbilical stays plugged in. If I wake up to a dead battery, no big deal as I am always a member of a Roadside Assistance company. It hasn't happened yet though as I have dual batteries in the 5er and the TV.

If your camper is on shore power no need to unplug the truck, in my opinion.