Car fuse poor man rig up

August 10, 2009 5:29 PM

How to turn my car's dome light off w/out pulling out the fuse.

I've got a car -- a van, actually -- whose interior lights won't turn off unless I pull the fuse out. If I pull the fuse out, my power windows don't work either. But it's a hassle to keep putting the fuse in and out. Furthermore, I cant afford to fix it right!

For under $5 or so, I'd like to rig something up where I can have a switch -- say, in the ashtray compartment -- such that flipping the switch on is equivalent to putting the fuse in, and flipping the switch off is equivalent to pulling the fuse out.

I need five things:

1. switch
2. wire
3. fuse (to hook up SOMEWHERE along the wiring)
4. MYSTERY DEVICE to hook the fuse up with the wiring
5. MYSTERY DEVICE that plugs in where the fuse used to plug in

I'd like help with (5) and (4) for sure, and possibly (3) if you think a different kind of fuse would be easier to install.

Thank you!!

posted by Eiwalker to Travel & Transportation (14 answers total)

Clarification needed, the lights are on all the time or only under specific circumstances, say when the door is open?

What is the make, model and year of the van.

Is this a known feature, or did this start happening ?
posted by iamabot at 5:30 PM on August 10, 2009

Is the instrument panel light dimmer turned up all the way? Sometimes there's a detente at the brightest level that switches on the dome light.
posted by stopgap at 5:33 PM on August 10, 2009

I'm having trouble picturing what you're hoping to do here.

You don't need to do anything with the existing fuse--just wire in your switch somewhere along the wire run from the fuse panel to the interior lights (is this a single dome light, or some kind of conversion-van runway-lights deal, or what?)
posted by box at 6:00 PM on August 10, 2009

To clarify, your dome light does not have a switch on it to control On/Off/Door, right? I've never seen one that doesn't have this.
posted by DMan at 6:04 PM on August 10, 2009

Best answer: Is your "Door Ajar" light on all the time, dude? From what you describe, that sounds pretty likely. Also, I don't see many automotive electrical faults that include a short to power without a blow fuse somewhere. If it was just one dome light, I'd say the problem is with that specific switch, but the most likely switch that can turn ALL of the interior lights on is a door switch.

To rig this up:
Get some wiring terminals that have exposed spade endings, like a fuse, or crimp your own on to match the fuse terminals. Plug one spade end into one side of the correct fuse location and run it to your toggle switch. Run the other side of the switch to the other side of the fuse. The polarity doesn't matter, since you're just completing the circuit. Make sure to include a correct amperage fuse in your circuit, preferably before the switch.
Tah-dah.
posted by Jon-o at 6:14 PM on August 10, 2009

Is this a GM model van? The knurled knob that controls the brightness of the dash light will turn on the interior dome lights when turned all the way up. Can you try turning this down/off?
posted by clarkie666 at 6:18 PM on August 10, 2009

I had another idea. You could run two switches in parallel to each other. That is, run two wires from one side of the fuse, each to their own switch and then back to the other side so you can have two points of control. One, a toggle switch in your console (just drill a hole in your ashtray and most cheap ass pep-boys style toggle switches come with a nut and washer for easy mounting) and the other can be a momentary contact (spring loaded, normally open) switch or button that you rig up on your drivers door so you can hold it down to run your windows up and down.
All five things you're looking for are available at a Pep Boys or Autozone. They'll be in the "Help" aisle or in whatever general electrical section they have.
Man, nothing makes a car truly "yours" until you run your own improvised shitty circuits. This is fun!
posted by Jon-o at 6:33 PM on August 10, 2009

also, in my experience it's pretty easy to pop out the lens that covers the bulb, so that you can remove it.
posted by ArgentCorvid at 6:39 PM on August 10, 2009

If I pull the fuse out, my power windows don't work either.
...
I'd like to rig something up where I can have a switch ... such that flipping the switch on is equivalent to putting the fuse in

So you want a switch that shuts off the light and makes power windows nonfunctional. Really?

No, I think you might be better off with a switch that just turns out your light. You can install a switch right near the light where it'll be easy to find the wire going to it without getting the windows involved. Buy thing 1 on your list, and you might need a little bit of thing 2. Skip 3, 4, and 5.

Bigger auto parts stores generally have a wider choice of switches if you would like one in a nifty color that lights up.

If you need a short bit of wire you can probably get some from a friend or out of some broken thing being thrown away. Look at the wire that's in car and use that kind.
posted by yohko at 7:06 PM on August 10, 2009

This may be (and probably is) something you've already checked, but have you made sure that the knob that regulates the brightness of your interior lights (in your dash) is not clicked to the setting that always keeps your dome light on, no matter what? I only think of it because several of my friends recently have been freaked out by this happening to them (their interior light staying on even with the doors closed), and it has always turned out they just have the brightness knob set to always have their light on. Apologies if you've already checked that-and good luck with any electrical work!
posted by scdjpowell at 7:09 PM on August 10, 2009

I would pop out the bulb for the dome. Then buy some tap lights and attach them to the ceiling. I'm assuming you want to go ghetto.
posted by chairface at 9:09 PM on August 10, 2009

I would get my hands on a Dual-Pole Single-Throw switch (DPST), a spare fuse, and a length of 2-conductor wire. Find a way to blow the spare fuse - short it across the battery terminals or something of the sort. Then, if it's a spade-connector type fuse, I would carefully drill a couple of holes into the plastic and through the metal, and find a way to connect one end of each conductor of the wire to the spade part of the fuse. If it's a tube-type fuse, you should be able to solder the wires directly to the metal on each end (but on the side, so it will still go into the socket). Then run the wire to where you want the switch, and cut it. Crimp spade connectors that will fit the blades on the bottom of the switch onto the end of the wire. Now, the switch should have 4 blades, 2 sets of 2. This represents the bottom of the switch:

                         +------------+
-------------------------|--/      \--|-[S
-------------------------|--\      /--|-[S
                         +------------+

Connect the wire to one pair of terminals, and the good fuse to the other pair. (The fuse is represented by the Ss here.) How to connect the fuse is left as an exercise to the reader. :->
posted by jferg at 5:01 AM on August 11, 2009

Best answer: Ok, following up to myself. Rather than the drill/solder into the spare fuse solution, assuming you have blade fuses, you need a couple of these:

Blade Fuse Tap - One piece crimps onto the wire, the other sticks into the fuse socket, and the piece crimped on the wire then connects to the piece in the fuse socket.

Also, for the fuse connected to the switch, you need:

Inline Fuse Holder - I suspect your local auto parts store will have something similar.
posted by jferg at 5:10 AM on August 11, 2009

Response by poster: Thanks Jon-o and jferg!

4. inline fuse holder

5. two male-end spade terminals
posted by Eiwalker at 5:55 AM on August 11, 2009