Title says it all -- I needed to add a circuit so I used a tap-a-fuse and picked the rear passenger window circuit as being pretty safe in case something went wrong (as opposed to the airbag circuit!). As it turns out, that circuit is always hot -- ignition off or on. That makes no sense to me since obviously the windows don't work when the car is off. I moved the tap to a different fuse and everything is fine -- circuit off when car off -- but it made me curious. What's up with the window fuse circuit being always hot?
Check the ground circuit with an ohm meter and see if its switched instead of the +. Some circuits interupt the ground for switching.
If I read the diagram correctly, you both hit the nail on the head. The power window interrupts ground for switching. Thanks! In the past I recall people asking about getting constant 12v in the interior of the car and I recall the answers were rather convoluted. Apparently, its quite easy. I'll add some key words so this thread will pop-up in a future search: CONSTANT 12v CONSTANT 12 volts CONSTANT POWER 12v POWER WHEN CAR OFF 12 volt POWER WHEN CAR OFF FUSE HOT
