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)


http://img168.imageshack.us/img168/4031/maplightyg5.jpg

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

 

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.

 

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

 

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!

 

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?

 

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.

 

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.