Continuous duty solenoid to cut power to 7 pin trailer plug

[Another JR]

You could do that, but wouldn’t it be preferable to just not connect to the 7 pin connector’s hot 12 volt pin on the trailer side of the connector?  That way the truck 7 pin remains in the standard configuration and you use your separate heavy gage charging connection for the campers or trailers that need it. That’s how I’m using mine. 
 

 

[RnA2021]

Hi Jon.     Yes, I could.  One way is to disconnect the battery + wire at the junction box on the inside frame of the trailer, and tape over the terminal.  The easiest and less risky way is to remove the fuse from the power distribution box.  Is that what you were thinking?

 

Thanks, Rick

[Another JR]

I don’t know the wiring on your trailer, obviously, but yes, any convenient and safe place you can disconnect that circuit path does the job.