Goal = Interior lamp on until start'n car

Hi,

I tried to do a search, but couldn't find clear information on this.  I'm trying to have the interior dome lamp stay on once I open the door until I turn the key to the start the car.  Then with the motor on and key in the "ON" position, the lamp should also turn on when a door is opened,  but turn off immediately after the door is shut.

With the motor off and the key in the "OFF" position, the lamp should stay on for a short period of time and then fade off by itself.

Most of the newer cars' lamps function like this and it would be nice to get my car to do the same.  Currently, it turns on and off with the opening and closing of the door.

Thanks in advance for your help.  This is a great site.

Simpson

I'm a newbie to all this, so work with me.  Would this work, or am I WAY off?

Man, I just realized that diagram is WAY off. 

Does anyone have a proven diagram?  Thanks again...

Here is one.

Thanks!  But since I'm EE illiterate, could you please explain the elements of the diagrams in terms of a SPDT relay pinout - where they go and what they are?  Thanks again...

You will need a Soldering Iron.

Thanks John!

A couple of questions: 

-what will energize the relay to give continuity between pins 87 and 30?

-and I'm guessing if the ignition switch isn't in the "OFF" position, the capacitor will not get charged up?

The Transistor conducts and sends a voltage to the Relay.

 As the capacitor discharges thru the Diode on pin 85 it slowly looses voltage until the Transistor finaly turns off and the Relay in turn shuts off too.