ok so im kinda picky for owning a base toyota pickup but what i want to do is use some knowledge to figure out how to make all the acc and stuff stay on for 15 min or until the door is opened my setup so far includes a 555timer (know how a timer works but dont know how to get the time i want with the resistors) but thats about it so far not sure where the initial signal should come from to start the timer... any suggestions