I could probably flip through my FSM and read the wiring diagrams, but does anyone know off hand if we can use something (like this)to save radio settings while the battery is disconnected? Also does anyone know if this would work to charge the battery as well? I have a trickle charger, but I was wondering if this device could serve a double purpose.

I know that when the keys are out of the car the cigarette lighter doesn't work. So most likely either the battery->cigarette lighter is switched or just the cigarette lighter is switched.
-hype

 

Yes it will work and your radio settings will be saved. But you will also have power (12 Volts) in your cars electrical system. If your disconnecting the battery to work on something electrical, putting that device on will make the electrical system live again. Kind of like putting the battery back on, only in a different location.

 

Ok then it probably wouldn't provide a path from the cigaratte lighter battery to the car battery since it sounds like the car battery is what gets switched right?
-hype