I'd like to have auto dimming interior lights - the kind that ... after the door opens, the interior lights come on full, and stay on, until door is closed - when door closes, interior lights automatically dim or fade to off over time (like 20 seconds). Any ideas? Could rob a mechanism from another car and wire it in, but not sure what I'd be looking for exactly. Anyone ever seen an aftermarket job anywhere?

 

I have that feature in my Bravada, the interior lights fade after a minute and the map lights in the overhead console fade after 2 mins.

 

If you put a capacitor across the light bulb the capacitor will charge up while the light is on and when the voltage is removed it will discharge keeping the light lit until the cap slowly discharges to 0 volts. The time it takes to discharge depends on the RC time constant. I'm not sure of the value cap you will need. I'll try and find out at work on Monday.

 

Cool idea! If you don't figure it out, I'll hit up my electrical guru friend of mine.

 

id defintly be interested in knowing how to do that as well, im not a fan of new vehicles, but the auto dim is sweet, along with the compass and temp rearview mirror which im getting soon

 

 

OK...For those of us who have ZERO knowledge of what IR, 555, SCR means...

How would this be built?

 

For just a nice dimming not sudden ON.....OFF.... a capacitor would work nicely. The feature for 20 seconds after finally dim and shut off would require a 555 circuit. Basically a timer circuit and that's all I know. Lucky me Stephen, I'm headin off to become an electrical engineer this fall.

 

I'd be OK with a sudden off. It would still make sure the interior lights weren't left on over night...Been there, done that!

 

A capacitor with enough capacity to keep a light on that long would be VERY large.

There has got to be a better way. I'm in an ECE class right now, I'll do my best to figure one out

 

I checked it out at work and your right I would need about a 5Fd Cap. An engineer I work with is going to see what he can come up with.

 

Another option is to use a smaller cap and drain it through a resistor. You would then need an IC to take the voltage decay and mirror it to an output.
Im gonna do some google searches and see if I can find one.
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I did some searching and found a guy that did what I described... Used an IC and a smaller cap to dim the bulb. Here is a diagram, should be able to build it with a few dollars at radio shack.
http://www.electronic-circuits-diagr...rsimages/3.gif

 

had a 86 camaro berlinetta that would do that if you had the headlights on and turned the car offthe exterior lights would turn off and the interior would come on and then fade out after you shut the door

 

my 85 has a timer for that.
It is very cool though, if you have the headlights on, and shut the car off, the headlights turn off and the interior lights come on. Then, they stay on for a minute after you shut the door, and then shut off. I may use this circuit so they fade out!

 

Sounds like we have a factory option, for something similar.

Any chance of figuring it out, and fitting it to other 3rd gens?

 

I'm not sure.
The lighting control is in a large "light module" located next to the computer. It controls everything, from blinkers to headlights to dash lights.
It has a pretty meaty wiring harness going to it as well.
I'm sure we could figure out how it works, but adding it to the stock harness would take some wiring.

 

i have that light control module if someone would be interested in it it has like 7 or 8 relays in it mounted to a circuit board

 

Try this circuit. To adjust the the brightness VR2 will adjust the initial brightness and VR1 will adjust the time to dim from full brightness to off.

The transistor used is a power transistor and will need a heat sink.


http://www.electronic-circuits-diagr...carsckt3.shtml

 

i love google don't you

here's a kit so you can have the auto dimming interior light

 

Thats a good link. I posted it earlier in the thread.

 

I am sorry. I suppose I was too busy laughing at the funny yellow smiley thingys.

 

Yeah - I googled the schematics for several - but I'm no electronics whiz - Solder and I don't get along! I was hoping I could just figure out what it was called, find a car make that had one, and go grab it at the boneyard or parts store.

 

Basically all the new GM vehicles have them. I'm sure you could find one that's totalled but the problem I'd have is to find the actual module that does the dimming. That's the next hurdle.... for me anyways.