How do I make my dome light fade away when you shut the door?

-
dilley340

dilley340

Well-Known Member
Joined
May 22, 2004
Messages
251
Reaction score
8
Location
Howell, MI
I was curious about what it takes to convert my dome light on my '73 Duster to fade-away after you shut the door, just like my Dodge Caravan.

Anybody do this before?
 
find a 12v capacitor, the bigger it is the longer the light will stay on, maybe radio shack will have something the right size. Take apart an old radio maybe you can rob one from there.
 
Well.........if you just stick a big huge cap across the lamp, it will take a BIG cap to provide any delay, but the PROBLEM is that when you OPEN the door, the cap will act like a "dead short" during it's charging cycle, and will be not only hard on your door switches, but may blow the fuse, too.
 
67Dart273 said:
Well.........if you just stick a big huge cap across the lamp, it will take a BIG cap to provide any delay, but the PROBLEM is that when you OPEN the door, the cap will act like a "dead short" during it's charging cycle, and will be not only hard on your door switches, but may blow the fuse, too.
Click to expand...

Thats what I love about this site, no matter what is said, someone disagrees.

Capacitors are what is used to make those dimming "auto" features work, sometimes, as far as the specifics of setting it up or engineering it properly, I don't care enough about it to invest the time. I was just giving the guy a place to start.

BTW I seriously doubt you know what "big" means relative to size of the bulb in the dome and associated wiring.
 
You would need different switches with more than one wire to control the current path.
 
fcm42000 said:
Thats what I love about this site, no matter what is said, someone disagrees.

Capacitors are what is used to make those dimming "auto" features work, sometimes, as far as the specifics of setting it up or engineering it properly, I don't care enough about it to invest the time. I was just giving the guy a place to start.

BTW I seriously doubt you know what "big" means relative to size of the bulb in the dome and associated wiring.
Click to expand...

I seriously think I DO

I was first licensed as a radio amateur before I was out of high school in 1966. I spend 6 years in the U.S. navy maintaining TACAN and ground controlled approach RADAR (GCA, or Precision Approach RADAR--PAR)

Caps and timing circuits are "what make RADAR work." I used to have a very good understanding of RC time constants

In my later years, I've repaired and modified a considerable number of amateur radio "linear" power amplifiers, all using very high voltage power supplies, and all using some fairly large filter caps in the power supply. We're talking anywhere from 2000-8000 volts DC across, say, 20-40 mics of capacitance. In other words, it can kill yer ***.

My point was..................and I still stick by it, ..............that if you just strap a huge cap across the dome light switch, it will probably "fix the switch" in short order.
 
Dude wasnt trying to insult your intelligence, didnt think that was something you would know of the top of your head. Seems like there would be some variables to investigate on the dome light system before you could just say it would blow fuses.
 
The current aircraft I am working on has a similar setup on one its the gauges to what I am envisioning for this dome light set up, I cant remember if it is parallel or series with the light.
 
67dart273 said:
i seriously think i do

i was first licensed as a radio amateur before i was out of high school in 1966. I spend 6 years in the u.s. Navy maintaining tacan and ground controlled approach radar (gca, or precision approach radar--par)

caps and timing circuits are "what make radar work." i used to have a very good understanding of rc time constants

in my later years, i've repaired and modified a considerable number of amateur radio "linear" power amplifiers, all using very high voltage power supplies, and all using some fairly large filter caps in the power supply. We're talking anywhere from 2000-8000 volts dc across, say, 20-40 mics of capacitance. In other words, it can kill yer ***.

My point was..................and i still stick by it, ..............that if you just strap a huge cap across the dome light switch, it will probably "fix the switch" in short order.
Click to expand...

dude!!! You were in the navy when captain crunch was an ensign!
 
67's Dart 273 knows it's just a RC time constant. You just need a capacitor with the correct micro ferade rating.
 
I tell you what, I will check in my stock room to see if I have any capacitors then I will experiment with some lights and my variable dc power supply, ok.
 
A google search on dome light dimmer turns up a good deal of do-it-yourself info including schematics and buildup walk-throughs.
 
Thanks for the input guys.

I'm not savvy enough to build one from scratch, but I appreciate the link slantsixdan.

The diagram that Cheddar Greg provided looks like there is a purchased timer module used. I looked on the related site, but didn't see it as being offered.

I wonder if the the delay is built into the newer lamps or if it's in the wire harness itself.
 
I'm trying to understand what purpose this would serve other than to look cool. I mean, when I shut the car door, I don't look back.
 
You must log in or register to reply here.
-

Back
Top