courtesy light delay

i wish to fit a delay to the interior light it has standard negative trigger from the door switch and a permanant positive supply.

any idea's or wiring diagrams would be appreciated thanks

the car is a 1989 porsche 944

the original interior light is a hella unit 1" X 3" with a 3 position switch (on-off-door trigger) negative triggered from the door switch.

In essence, this circuit is a 15 to 20-second courtesy light extender for cars. It is activated in the usual way by opening a door but it also samples the negative lock/unlock signals from a car alarm or central locking and does two more things.

First, when an unlock signal is received, it turns on the courtesy light for 15-20 seconds before you open the door. Second, when a lock signal is received, it turns off the courtesy light immediately, with no fade-out. This is done to eliminate false triggering of the burglar alarm through current drain sensing.

That looks very good and I will try out what you have suggested.

How can you modify the circuit so that when you turn the IGN off the interior light comes on.

Also if the doors are closed and you turn the IGN on the interior light turns off. (also so that if the IGN is on that no delay is present if the door has been opened and then closed the light will go out once the door has been closed)

Thanks for your info.

Samis to do both of the things you wish to do properly you will need to build a more complicated driver circuit using an ic chip like a 555 timer.

but it is posible using a couple of relays and making them positive triggered from the ignition instead of negative triggered from the c/locking.