bblhed

Like a lot of people I have installed Cold Cathodes in my xA. I really like them. But I don’t like the way that there is no light on the floor of my car when it is shut off and I am getting in or out. I came up with a solution to this problem that really works great. I have added a relay and a diode so that when I open the door the cathodes come on. Along with that I still have my original set up that allows me to switch the cathodes on and off any time I want to if the car is running. I think this is a nice solution to the problem. Here is the schematic.


click on pic for larger image

Burnout

Nice diagram! Here's an alternative......instead of wiring into your cig lighter, you could tap into the "blue plug" under your center console for power. This way, they would come on automatically when you turn on your parking / headlights. The switch you show would be used to just shut them completely off.

bblhed

^^^ I had that thought originaly, but I have my cup holder Leds hooked up that way, and I really didn't want to have to turn on the parking lights just to turn on the cathodes. This set up allows me to turn on the cathodes as long as the car is turned on (Still kind of a pain but prevents me from killing the battrey with them). Also I have the advantage of finally having lights on the floor under the dash and back seats where I desperatly needed them when I get in and out of the car that come on when I open the door.

Oh yeah, the relay I used is a Radio Shack 12VDC, 6A Automotive Relay. It is a bit loud, but for $5 I can live with it.

rebelMan

what would i do differently on an xB being that i do not have an oven light?

bblhed

Rebel Man, you would just have to follow my diagram, but insted of taping into what I have to admit are the quite convient oven wires, you will have to tap an always on positive, and the switched ground of an interior light that comes on when the door is open.

rebelMan

ok ^_^ I would put an LED in the oven, but my HU is going in there to make room for the CarPC touchscreen in the dash ;(

So i would have use a relay between the door ajar light in the instrument panel and a positive wire going to my interior/exterior lighting. Then the lighting would also have a positive feed from the cigarette lighter (or parking lights) and have a switch after that in case i wanted to turn it off for any reason. Is that how it works? Like your setup, key is to ON or ACC your lights are on right? (unless the switch is off). But beyond that, when you open the door the relay "opens" to turn on the lights until all the doors are shut right? I'm a noob and i don't really know what a relay is >_<;

bblhed

RebelMan, I was once like you and thought that all this electrical stuff was too hard for me too. Then I decided that there were too many cool things I couldn't do because I didn't know antthing about electronics so I learned. I vowed to teach others, unfortunitly I have learned recently that I have a rather short fuse, and get really Ticked off when I try to teach something and the person I am explaining it to doesn't get what I am saying.

I will tell you this.
DO NOT HOOK to the led in the dash. That can only end badly for you.

A Relay is a switch that is activated when power is applied, you ues them for lots of reasons, I used the relay in this set up because I had negitive that was switched, and I needed to have switched positive.

As for switches, When a switche is ON it is "Colsed" and when it is OFF it is "Open". So when I open the car door the relay switch is Closed. This is easy to remember, just think of the contacts in the switch, when they are open there is a gap between them and power does not flow, and when they are closed there is no gap and power flows.

Good luck.

rebelMan

makes sense, thanks. Why is hooking the LEDs in the dash bad? I'm not understanding that part sorry

bblhed

The Door ajar LED in the dash is on a PCB, not hooked to wires, getting to that LED will not be plesant at all. Next once you do get to the LED it is not driven by a full 12VDC, it is steped down through a resistor some place so you actualy have to find the feed power for hat resistor, then you have to figure out where the wire is so you can tap in, or solder to your insturment PCB, it will be a hassel, and there are a lot of chances for mistakes to happen. Your best bet is to find the wires that run to the front dome light and tap into them. You will save yourself a lot of trouble. Also remember test everything as often as possable wile doing the reassembly.

rebelMan

Oh ok, i know when i instaled an alarm on my echo, i tied into a wire at the top of the fuse panel (inside) that was the door ajar light. I think it was for the dome light not the instrument panel though. Now i get it ^_^

z-lite

Trouble is finding the wire the goes to the dome light. Sounds like a stupid experiment but maybe we can short the dome light and then find the fuse that popped and tap into that?

rebelMan

I'll check in the manual, i'm sure it's in there. I got a print out off all the interior wires from an I.C.E. shop locally for my Echo. If a wire chart exists for an echo then yea, the scions have them somewhere ^_^

bblhed

I can not stress this enough. JUST ABOUT EVERY CAR EVER MADE THAT HAS LIGHTS THAT COME ON WHEN THE DOOR IS OPENED USES SWITCHED GROUND TO MAKE THE LIGHT COME ON! In a car that was built in the last 30 years there is always constant on positive power at the light that comes on with the door open, and door switch switched negative! Unless you are working on a British car that was built pre 1970 this is always the case. This is why I get all mad about this, people think I am lyeing when I say that dome lights are negative switched because it is counter to the way everything else in the car except the horn works, but this is the way dome lights have always worked. If you look at a Factory Horn Wiring diagram, you will see that it works almost exactly the same way as my door open cathodes.

Reason Ahead.

The dome light is "Frame Ground" Switched for several reasons.

1. Only one wire needs to be hooked to the switch.
2. Less risk of a problem if the switch gets wet.
3. Fewer wires, fewer chances of wire problems.
4. Fewer parts in the switch to fail
5. The switch is screwed right into the ground point.

I told you I have a short fuse when it comes to this, didn't I?

rebelMan

makes sense

z-lite

So the question is, how do I get it to work in a tC? The oven light won't turn on unless the light switch (behind the steering wheel) is set to parking light/low beam mode.

bblhed

As I said in one of my above posts, I only used the oven light wires because, well lets face it they were right there. What you need to do on any car is what I did on the xA.

Simply find the most convient place to tap into the switched line for the dome light.

I got luckey on the xA because it was in a REALLY easy spot, plus I have ALL the factory books for the xA so I knew what wires did what before I want in.

I would be willing to bet that on the tC and in the Box the wire for the door switches runs through the trim at the base of the door, and up inside the kick pannel under the dash. The hard part will be finding it. I really miss the days when the dome light switch was in the forward part of the door jam, the wire was easy to find then.

VelvetHammer

Thanks for this. Hopefully this will help in my JLevi Puddle lamp installation on my tC. I want them to come on when I unlock my doors with the keyfob.

bblhed

Bump

ReyS739

interested.....

bblhed

Bump