On my 1997 f150 stepside I am trying to hardwire an inverter into the system. I am trying to find a source of power easily accessable under the dash. I have thought of trying to tie it into the lighter socket, but the power doesn't shut off when the car does. This would mean I would have to kill the inverter myself. I would like to have the power source shut off when the car does so it won't kill my battery. Thanks in advance for any help.