unplug my wire harness?

Unplugging or not is one of those why chance it things. Unplugging is easy enough to do. Why chance it. I always unplug. I don't really care if the system is supposed to be isolated or not. If I unplug I know it is isolated. Unplugging is 1000% foolproof.
Waking up with a dead TV battery would be a huge pain.

Dead TV battery?...It can happen. The RVer I spoke to tried running his trailer heater all night.Totally dead TV battery in the AM.

I always unplug mine,even if we don't unhook. As far as forgetting to reconnect,I would know right away as we always do a light and brake check prior to getting back on the road.

Could staying plugged in kill my two TV batteries? I don't know,but do not want to find out!

Fords have isolators built into the truck. GMC and Dodge do not.

I built my own isolator and put it into my (former) 5er and my current TC so I would not need to void the warranty on my (at that time) new truck

There are also off the shelf isolators. Here is one: Clicky

Or you can be cheap and plug and unplug it. But make sure you remember to do so!!! Forget to plug it in and you dont have brakes and running lights on the trailer. Forget to unplug and you could have a dead battery on your tow vehicle. I think the investment in an isolator is cheap insurance.

Owned 4 Chevy trucks over the years and they were always hot. I never unplugged any of them and never had a problem with the batteries going flat. I will continue to never unplug while I'm hitched up and suspect I will continue to never have any problems. :W

I have always unplugged from the truck especially if I am going to plug into shore power for the short overnight stay. Just precautionary to avoid feed back from the converter into the truck system.

Your TV is a GMC.

Charge wire is always hot.

Unplug it.

The danger if you leave it plugged in is that the RV's electrical needs will flatten the Truck's battery.. Of course the truck SHOULD have a device called an isolator (it is very easy to check if it does) which functions to prevent this.

How to test

you need a test light.

This is a ice pick like thing with a lamp in the handle and a wire lead

Ground the wire lead (Any handy ground point)

Touch all 7 pins in the truck's connector, one at a time (engine off, no lights on, no brakes on save perhaps the parking brake)

NO LIGHT.. GOOD It's working.

ONLY unplug if you unhook.. If you unplug and do not unhook it is possible you may forget to re-plug.

I always unglug and store in drivers seat. A fellow RVer had their harness taken one night while they sleeped in rest stop. Not as much a safety issue as a pocket book issue.

Your Chevy will remain hot at the plug when the eng is off. However, when we stop for just the night and don't expect to be using a lot of battery(s), I just leave it connected. It doesn't hurt anything to draw the trucks batteries down 10~20%.

My plug for the Ford was dead when the truck engine was off. My Chev stays on when the engine is off. I unplug the cord. Why take the chance. Put a note on the seat reminding you to plug back in.