Disconnect power cord from tow vehicle?

[JosephC]

If stopping overnight in a rest stop or other location until morning, without an electric hook-up, is it necessary to unplug the tow vehicle power cord in order not to draw from that battery?

[RogerR]

Maybe? Great answer, huh? Well on some vehicles there are automatic cutoff to avoid battery drain. On others, none.

You might get an answer if you post your exact year, make and model of tow vehicle.

I never had a problem with my Jeep Grand Cherokee Overland 2014 but that was always for one night anyway.

Your owners manual may help.

[CAG]

Maybe, or maybe not but it would not hurt to unhook. I don't think you need to go to all of the research to be sure. Just unplug it and plug it back in the next morning.

[TxLoser]

If in doubt, disconnect. I do with my Chevy, but I honestly don’t know if it cuts off or not. I’ll have to take a volt meter to the plug sometime when the truck is shut off. You’d think most modern vehicles would cut it off after a period of time.

[Happy wife / happy life]

Originally Posted by JosephC

If stopping overnight in a rest stop or other location until morning, without an electric hook-up, is it necessary to unplug the tow vehicle power cord in order not to draw from that battery?

I have a old school truck ( 1984 ) I installed a solenoid that cuts off the power from the tv (tow vehicle)to the tt (Travel trailer) I tied it to the ignition switch. I don’t unplug. I think if you tell these folks what year, make and model truck and trailer you have they will be able to give you a lot more information than I can.

[Jim Davis]

Also was the charging wire an add on.On my Toyota Highlander it was added when the seven pin was installed. It is hot through a 30 amp breaker from the positive post.

[JosephC]

The tow vehicle is a 2021 GMC Sierra 2500., gasoline.

[RoadrunnerII]

Check your manual on the truck.
Pretty sure it is disconnected on ignition off.
Most HD type trucks are.
Our F250 uses a separate fuse for the trailer battery charge line with relay

RoadrunnerII

[TWP723]

I guess the biggest concern unplugging would be forgetting to plug back in the next day. I'd unplug regardless, then just make a reminder to plug it back up.

[SkyBound]

When my trailer is plugged into the truck, it says on my dash display that the trailer is connected, tells me what my brake gain is set to, etc. Yours should do something similar. If you forget to plug it in, you would probably notice by not getting the usual towing screens and messages that pop up when connected.

Also, every time I start a tow, I grab the manual brake gain lever and give it a little squeeze to make sure trailer brakes are working. Without being plugged in, nothing would happen.

I would absolutely unplug overnight just to be safe.

[Scott]

Originally Posted by SkyBound

Also, every time I start a tow, I grab the manual brake gain lever and give it a little squeeze to make sure trailer brakes are working. Without being plugged in, nothing would happen

I do this too.

I also visually inspect my hitch connections to make sure no one messed with them while I was stopped. Happened to my Dad once. Someone unplugged his trailer brakes wire, his emergency brake disconnect, and took out an equilizer hitch pin. Glad he caught them before he pulled out of that rest stop.

[kirkelli]

I actually have a relay switch that toggles my tow vehicle charge line off/on. I originally installed the switch to toggle the charge line when i am using my DC/DC Charger but also found it useful when stopping at rest stops for quick lay overs.

[Marine71-76]

We have never ever disconnected our tv from our trailers - had 2 different TTs and on our 4th 5vr when stopping overnight. We had a 1974 Plymouth 'Cuda for the 1st TT and 1990 Dodge Ram Van with the 2nd TT and F350 and now F450 and never had a problem. We always walk around in the morning to verify everything is still hooked up. Of course, we do put a padlock on the hitch because we know of people who have had their hitches played with - even cousin's tractor trailer!

And for those wondering, the '74 Cuda - 4 on the floor and yep, burned up the darn clutch! But boy did we have fun.

[16WhiteColly]

I would, if in doubt, might save your TV battery.

[craigav]

Originally Posted by TxLoser

If in doubt, disconnect. I do with my Chevy, but I honestly don’t know if it cuts off or not. I’ll have to take a volt meter to the plug sometime when the truck is shut off. You’d think most modern vehicles would cut it off after a period of time.

In line with the TxLoser, I highly suggest that all RV'rs carry a voltage meter with them for all types of issues that could occur. With a voltage meter the answer can be easily determined. If when the truck is turned off and key out, and you still have power at the connector then that power is coming from the truck's battery and will lead to a dead battery if you run the trailer lights and other 12v items long enough.

Keep in mind that the image here appears upside down to what I remember (you can line up the slot to be sure of the orientation), in any case, if there is 12v power to any of the connectors with the key off and out, then you will run the risk of draining the TV battery if the trailer remains plugged in when camping. ~CA

[TxLoser]

Just tested my ‘19 Chevy 3500. No power with the truck off.

[Jagiven]

My truck has the ability to keep the aux power hot all the time, and that is how I have it set right now.

Typically I disconnect the 7 pin. Check the hitch and everything thing else in the morning before hitting the road.

Last fall we had some serious landscaping done. Each morning I pulled the trailer out of the driveway and parked on the street. One night I did not disconnect the 7 pin. I did not plug back into shore power that night either. Morning came dead truck and TT battery. TT battery was 9 years old, and bit the dust that night. In the process drained the truck battery. Luckily the booster pack was able to start the truck. Just a friendly reminder why I should make a habit to disconnect the wire harness each night.

[JimHanus]

I always disconnect (2013 Chevy Tahoe) just to be safe. On mine with the engine off the vehicle battery and trailer battery are still connected to each other. Same with my old Jeep Grand Cherokee. I had a radar detector plugged into the cigarette lighter and it would beep on when I connected the trailer plug.

[Leon]

Never had a a problem with that never have disconnected mine ..no worries
That power feed wire is on all time truck on or off but it charges your house batteries when driving but RV’s don’t draw from it anyway not designed for that .My snowmobile trailer is designed with interior lights that will work off the charge wire .There is no batteries in that trailer which is different .Have remember to shut lights off
You should have sufficient charge in your hose batteries to camp over otherwise if they are low nothing is gonna work in your RV anyway either have go buy new batteries or fire up a generator

[Stever71]

I leave mine connected to my 18 GMC Sierra when trailer is connected to shore power.
Reason being i use my truck as a wifi hotspot for the kids which was draining my truck battery.
When connected to shore power the trailer keeps my truck battery charged.
Kind of reverse situation from rolling down the highway.
The charge line must be connected all the time even with ignition off