First, what is so very special about the light dimming out, except that it shows more "class:??? And if the cardoor is left open all night then a dead battery in the morning will help you to remember to close the door next time. That is a task for the body control computer. To turn the light on with a momentary push of a button is simple, but probably no module is available to do it. The button charges a large capacitor that piases the gate of an FET to switch on and power the light, then when the charge bleeds off the light goes out. Very simple but you need to build it yourself. But that is not hard. But where to install it in the car so it will not flop around and short circuit to something??

 

How long do you need the lamp to stay on?
Is the door light turned ON by grounding one side of the light or switching +12 volts to the lamp?

I was thinking of an "on" time around 5 minutes. But, even a minute or so would probably be ok.

Good point about the present switching! Dang, I would not be surprised at all if the ground is closed or opened. I can check tomorrow.

 

First, what is so very special about the light dimming out, except that it shows more "class:??? And if the cardoor is left open all night then a dead battery in the morning will help you to remember to close the door next time. That is a task for the body control computer. To turn the light on with a momentary push of a button is simple, but probably no module is available to do it. The button charges a large capacitor that piases the gate of an FET to switch on and power the light, then when the charge bleeds off the light goes out. Very simple but you need to build it yourself. But that is not hard. But where to install it in the car so it will not flop around and short circuit to something??

Uh, I don't give a rat's you know what about dimming or "class" (on a 14 y/o car w/ over 250k miles on it), I just want the door panel light to turn on automatically as usual when the door is opened, triggered by the switch in the door, and then turn off after several minutes with very little or no current drawn after turnoff (including by the control circuit), in case a door doesn't get closed completely. (That could be me or my wife, or I might be working on the car w/ the door open for a good while... but we also have a teenage daughter using the car a lot, with all that entails...) (Well, heck, when I was her age I had plenty of "distractions" too, just not as many?)

At turn-off the whole thing automatically resets and then waits, looking for the next door opening.

Indeed, such a shutdown IS is a task for the body control computer, but for whatever reason Subaru didn't include it for the door panels' lights, or, for that matter, the rear (hatch) dome light.

Installation is not a problem. I used to do a LOT of quite meticulous customized car stereo installs. None in the 10+ KW range tho'...

 

OK, if the present arrangement is the door switch closing to ground the light then the capacitor charge is a bit different. It will take a bit of thought.

 

Tracing the wiring turned out to be a pretty significant challenge, but one of the regulars at subaruoutback.org was able to very kindly provide the schematic, and the basic hookup is: Fuse > Lamp* > Switch* > Gnd.

*The "-" side of the light = "+" side of the door switch, and it also feeds the computer.

 

OK, now that the circuit is known, the actual requirements become clear, but not that simple:
1. Switch on the light immediately when the door switch to common negative closes
2. Switch OFF the light immediately when the door switch opens.
3. Switch OFF the light after a set time delay even with the door switch is closed, Do not draw any current .
4. Reset the time delay immediately when the door switch opens, but do not switch on the light.

 

Righto, it's not "simple" unless stealing a trigger from the dome light or a map light, but even then there's the complication of the local switching @ the map or dome light...

P.S. Apologies for the slow reply. My brother somewhat suddenly passed away, no will, no planning / statement of intentions, etc., and I'm the eldest immediate family member / eldest son. ......Messy.

 

Righto, it's not "simple" unless stealing a trigger from the dome light or a map light, but even then there's the complication of the local switching @ the map or dome light...

P.S. Apologies for the slow reply. My brother somewhat suddenly passed away, no will, no planning / statement of intentions, etc., and I'm the eldest immediate family member / eldest son. ......Messy.

My deep sympathy on your brother's passing. The pain is always a lot, and the disruption is always excessive.
Last January I lost three friends, the widow of my best friend is still struggling to maintain ownership of the house they lived in. The disruptions are always the nightmare, aside from the pain of the loss.

 

This could be a good place for a micro-controller module, arranged to power on the light and run the program whenever the door switch closed, and to power off whenever it switched off the light power.The timing accuracy would not need to be precise at all, just sort of repeatable, really just two timers and a bit of logic. One processor , one mosfet, four leads: +12, common negative, switch, and light. And it can be housed in a blob of epoxy.
The functions as described in post #26.

 

I found a similar discussion here:

https://forum.allaboutcircuits.com/...-around-10-minutes-for-interior-light.144999/

try this circuit:

https://forum.allaboutcircuits.com/...d-10-minutes-for-interior-light.144999/page-3

The power source would be tapped off your courtesy light power control circuit.

 

try this circuit:

https://forum.allaboutcircuits.com/...d-10-minutes-for-interior-light.144999/page-3

The power source would be tapped off your courtesy light power control circuit.

Thanks. The circuit in post 45 looks interesting if (IF!) I am thinking about it clearly.



https://forum.allaboutcircuits.com/...inutes-for-interior-light.144999/post-1235355

 

Certainly this is an interesting circuit but I do not see it as applicable to the requirements as I understand them, described in post #26. We need to see the rest of the circuit, including the relay connections , and the door switch that has one side connected to the vehicle negative ground.
I have not yet had my morning coffee, it is only 4:25AM. So possibly I am missing something here. Certainly the rest of the circuit is missing.

 

Per the request of the TS, a larger image.
D1 and D2 are over/reverse voltage protection, so may not be needed if the power input is "clean".
M1 inverts the 555 output to switch the "high side" M2 mosfet so a convenient ground connection can be used.

 

Per the request of the TS, a larger image.
D1 and D2 are over/reverse voltage protection, so may not be needed if the power input is "clean".
M1 inverts the 555 output to switch the "high side" M2 mosfet so a convenient ground connection can be used.

View attachment 311265

View attachment 311266

Thanks!

My apologies for the slow reply - my next youngest brother passed away suddenly, 800+ miles away, and he'd made no arrangements, no will we know of, he'd very recently moved and records are lost, and I'm eldest son -- I'm getting good assistance from my other brother (youngest son) but there are no other relatives who can help. So, I've saved the schematic and bookmarked this thread but it may be a bit B4 I can get back to this. Thanks so much to everyone!!

 

Thanks!

My apologies for the slow reply - my next youngest brother passed away suddenly, 800+ miles away, and he'd made no arrangements, no will we know of, he'd very recently moved and records are lost, and I'm eldest son -- I'm getting good assistance from my other brother (youngest son) but there are no other relatives who can help. So, I've saved the schematic and bookmarked this thread but it may be a bit B4 I can get back to this. Thanks so much to everyone!!

Sorry for your loss. My condolences to you and family.