need help wiring in a map light

I undertook my project of adding a map light assembly into the headliner of my 98 civic LS today. I had to remove all the upper interior trim to pull down the head liner, but it wasn't too bad. I mounted the map light assembly and have put everything back together. I haven't figured out the wiring, maybe someone here can help.

My Civic LS 4D is a '98, the dome light has two wires only. One leads to the battery + , the other comes from the door switches. (I have the '98 wiring diagram) The grounding comes from being screwed to the metal frame of the roof.

The map light is from a 2001 Civic EX 2dr. There are 4 wires (see picture)

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From looking at it, I'm thinking black is ground, red is (+), but there is still blue and green. Green is possibly for the door switch lead, but what about blue which is tied into yellow (thus tied to white)?

I have to make four wires become three. I'm either going to have to tie two or leave one out. Anyone have any clearer idea of this than I do?

Thanks

Reply to
Kevin Van Sant
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As a follow-up, I decided that blue and red were both (+) so tied them together to the (+) lead. Black was ground, green was door switches. I wired it up this way and the map lights work, the original dome works, but the new dome blows the fuse when I turn it on. The new dome is what's related to the blue wire (if you look at the picture it should be clear) So evidently I can't just tie it to the red, although if I exclude it there is no (+) lead to the new dome light. Can anyone figure out how I might wire this differently? Thanks.

Reply to
Kevin Van Sant

I think that you would be better served if you could make a schematic of the wiring. Once you have a correct schematic it will be obvious how to modify as required. MLD

Reply to
MLD

Having the correct circuit diagram for the 2001 civic would be nice--I'm sure someone reading this thread must have the service manual... so maybe they'll shed some light on this.

Anyway, from the picture and some guesses I made as to what is under the black insulation on the top, my thought is that the green and blue are "conditional grounds", meaning that both green and blue will connect to ground for given conditions.

Rationale: it looks like the yellow wire on the right-hand side of the center dome light is the + voltage supplied via the left terminal on the right spot light. The left yellow wire on the center dome must be the "path to ground", so that means that the blue wire (directly connected) and the green wire (via the switch in the "Door" configuration) must ultimately lead to a ground.

Since the green wire is connected to the "Door" setting on the control switch, I'm guessing as you did that the green wire goes to the door switch, which is probably closed when the door is open, causing the green wire to lead to ground and the light to come on.

I have no idea what conditions (in the original 2001 vehicle) would cause the blue to lead to ground, but it seems like connecting the blue and green wire together would make sense. I'd be interested to find what the mystery blue wire is supposed to connect to. Good luck!

Reply to
Greg

On second thought, if you tie the green and blue together, then the light will always act as if the switch was on the "Door" setting since you'd be circumventing the switch. Did you try just using the red, black and green and not using the blue wire at all?

Reply to
Greg

thanks for your thoughts. I think you have it figured out correctly. As a matter of fact I did just that earlier today and that was the ticket. I just dead ended the blue wire. And everything works perfectly as it's supposed to. I'm really happy with the success of this project. I've never ripped apart my car to do something like this before, so I'm partly relived that I got it back together without incident. And the map lights are much more useful than the dim center dome.

Reply to
Kevin Van Sant

Very cool! I'm glad it worked out, although out of curiosity I'd still like to know what the blue wire is supposed to connect to in the original 2001 car.

Reply to
greg.berchelmann

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