I use a Garmin GPS in my truck. When I turn truck off, both dash outlets, lighter and accessory, are hot, but sometime later they shut down. I want the power to stay on to my GPS, and don't understand why the 12v accessory power goes off Long after I shut truck down. Next step I think off is to run a dedicated 12v line from battery to GPS. can anyone here explain Why the lighter and accessory plugs switch off an hour or 2 after I switch truck off. Thanks

 

They switch off because of the accessory delay relay.

 

 

Just be careful you don't kill the battery.

 

GPS mounted on my motorcycle can stay on all week and not kill the battery. I think the truck batt will be ok.