Focus Fanatics Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
487 Posts
Discussion Starter #1
alright im sure this has been asked before but how would i go about wiring extra lights to come on only when the over head dome light is illuminated Im looking at getting some accent lighting to put under the dash from oznium.com but I only want it to come on when I switch the dome light on or it comes on automatically
 

·
Registered
Joined
·
675 Posts
You can tap off the fuse that lights them. Or splice into the wire that GOES to the interior lights which is almost as easy. Either way, as long as you don't overload that circuit, (IE: use LEDs, NOT incandescent bulbs so you don't overload it) then you can do either. You can probably put about 1 point 2 Jiggawatts of LED light in there tapping off the fuse or wire for the dome light. Especially if you replace the dome light bulb with an LED too.
 

·
Registered
Joined
·
2,928 Posts
I think some open the A pillar and tap into that wiring. I just tapped into the center bulb contacts and ran wires under the headliner. I've got some red lights to illuminate the hatch area for now. I'll get around to the right color sometime. When I use the fob, the overhead and rear lights illuminate, and also from the switch inside.
 

·
Registered
Joined
·
675 Posts
I think some open the A pillar and tap into that wiring. I just tapped into the center bulb contacts and ran wires under the headliner. I've got some red lights to illuminate the hatch area for now. I'll get around to the right color sometime. When I use the fob, the overhead and rear lights illuminate, and also from the switch inside.
Yep, there ya go! On blade fuses, one can tap in there as well. But tapping into the wiring IN the cabin has it's benefits.
 

·
saved from the grave
Joined
·
6,106 Posts
A-pillar for me but I can't remember the colors. You can take out your dome light and get the right color combos and take off the drivers a-pillar and you will see black tape over the 3 wires that run over to the dome. Tap into those and you are good.
 

·
Registered
Joined
·
675 Posts
A-pillar for me but I can't remember the colors. You can take out your dome light and get the right color combos and take off the drivers a-pillar and you will see black tape over the 3 wires that run over to the dome. Tap into those and you are good.
Damn, now I have to get off me arse and do this to mine. [headbang][giddy]
 

·
Registered
Joined
·
675 Posts
I added a rear domelight to match the front on my zx5! Works just like factory using the fob and all.
Yep, because that circuit is powered buy a common hot that energizes when the key fob is pressed to unlock or the door is opened. They are triggered by the dome light circuit so anything wired in series with them will work as if wired stock....but remember, use LEDs! Too much current draw on that circuit can cause a fire or at the very least the fuse to keep blowing.
 

·
Registered
Joined
·
487 Posts
Discussion Starter #9
does anyone know what collor wires I witch I ran a positive from the orange and grey to the positive on my l.e.d's and then my ground wire to the solid black and the lights stayed on the entire time I then tried switiching my power to the blue and grey striped wire and the l.e.d strip never came on [scratch] Edit. when I have my power going to the black/blue wire and my ground to the black when the switch is in the middle position the cathode glows faintly at the one tip ofi t
 

·
Registered
Joined
·
487 Posts
Discussion Starter #10
another edit. broke the dmm out and found at the over head light im only seeing 2.7 votls. the over head light is just as bright as it should be but is this normal? im only seeing 2.7 volts at my cold cathode transformer wich is why I think its making it not light up.


Now I know very little about electrical but could I run a relay so that the 2.7 volt would activate a relay switch and send me 12 volts? I could run the 2.7 volts from the turn on wire for the over head dome and a constant 12 volt from the fuse box would this work?
 

·
Registered
Joined
·
675 Posts
another edit. broke the dmm out and found at the over head light im only seeing 2.7 votls. the over head light is just as bright as it should be but is this normal? im only seeing 2.7 volts at my cold cathode transformer wich is why I think its making it not light up.


Now I know very little about electrical but could I run a relay so that the 2.7 volt would activate a relay switch and send me 12 volts? I could run the 2.7 volts from the turn on wire for the over head dome and a constant 12 volt from the fuse box would this work?
getting overcomplicated here....what did you test?
 

·
Taciturn. Your turn.
Joined
·
2,210 Posts
You're getting way too complicated. I added a rear dome and two footwell lights, hardest part was running the wires through the interior.

If I recall from the top of my head....
orange/blue - 12v constant (this is on the battery saver)
black - constant ground
black/blue - door ground/dimmer

So if you want door lights use the orange/blue and black/blue wires.
 

·
Registered
Joined
·
487 Posts
Discussion Starter #16
getting overcomplicated here....what did you test?
Alright I got I use a better quality dmm. There is 3 wires going to the overhead done light the constant 12v, the common ground, and te wire that I only activated when the door opens,closes, or you unlock the doors. I tried to tapp into the wire that is only activated when the doors open or the key is unlocked but after taping into it and wiring it up to the power wire on my cold cathodes transformer the cold cathode hardly lit up I expected A low voltage and after metering it at the end of the wire where it meet the cold cathode transformer and at te actually over head some light I wa only seeing .02. To .03 volts the wirebim referring To us the blue black one sorry for not verfying
 

·
Registered
Joined
·
3,365 Posts
mitchv >> it is late, I am a bit into the spirits, but I will try to help as you say you don't have a lot of experience with electrical. OK. HEre goes. If your measuring 2.7 volts, then your not measuring to ground. OR, your measuring AFTER or between to bulbs. A bulb or LED 'drops' voltage across it. So you just have the wrong points your measuring from. OR >> you have the meter set up wrong (hey! it happens). It is useful to think of voltage/current as 'potential'. you have a known potential of ~12v from your battery. You just need to I.D. that 1st (your source voltage), then work you way towards your lamps. REMEMBER!!! Do not assume a 'ground' is always true. Especially in a car. Our focus (like all modern cars) have some 'switched' grounds.
Hope that helps a bit. (Errrp!)
 
1 - 18 of 18 Posts
Top