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Discussion Starter · #1 ·
Hey guys,

I know at least one of you has added courtesy lights to your car. What I'm wondering is this...

I'm about to add a CIPA 36500 Auto-dimming/compass/outside temperature/map light mirror, and it has the ability to use the map lights as courtesy lights as well as map lights.
So, where is a good place to access a 12v Courtesy Light wire? My car did NOT come with sunglasses holder/front map lights already, so the only courtesy light I'm aware of for my car is my dome light. Please don't tell me I have to take off my whole darn headliner.

Help! haha
 

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Why dont you pull the driver "A" pillar garnish and see if harness pass through there on it way to junction block there in the dash ??
 

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Discussion Starter · #3 ·
I'll prolly end up pulling off the A and B pillars trying to find a courtesy light wire. Just wondering if anyone knows for sure. Burnitwithfire?
 

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QUOTE (bloodninja @ Nov 28 2010, 11:36 PM) index.php?act=findpost&pid=375432
I'll prolly end up pulling off the A and B pillars trying to find a courtesy light wire. Just wondering if anyone knows for sure. Burnitwithfire?
A pillar, that's where I spliced mine in. I wanted to be sure I got the right wire and didn't feel like chasing wires under the fusebox.

Three wires inside that small harness


Red is power.
Black is ON ground
Blue is the dimmer ground (goes to the BCM)

Don't splice directly on the blue wire if you plan to use the dimmer ground. You should splice at the bulb like I did.
 

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Discussion Starter · #5 ·
Thank you so much. What's the reasoning behind not splicing directly on the wire, but splicing at the light bulb? Does it affect operation if you splice at the wire?
 

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QUOTE (bloodninja @ Nov 29 2010, 07:31 AM) index.php?act=findpost&pid=375468
Thank you so much. What's the reasoning behind not splicing directly on the wire, but splicing at the light bulb? Does it affect operation if you splice at the wire?
I wanted the additionnal lights to be controlled by the dome light so I had to ground them between the bulb and the switch. Doing it after the switch (in the A pillar for example) meant they would need a separate swith or they would always be on.
 

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Discussion Starter · #7 ·
Ohhh. Thanks. But then how did you run the wires from the dome light back to the pillar? Did you have to remove the headliner?
 

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So if one would be satisfied with them just being controlled by the door switches and don't necessarily have to have them switchable via the dome light switch...  Would it work to splice in to the dimmer ground wire for ground and just run a separate hot to the lights?

Now that my car is getting old, almost paid off and warranty almost gone I might as well have fun with it... :grin:
 

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QUOTE (hoosieraccent @ Nov 29 2010, 08:37 PM) index.php?act=findpost&pid=375642
So if one would be satisfied with them just being controlled by the door switches and don't necessarily have to have them switchable via the dome light switch...  Would it work to splice in to the dimmer ground wire for ground and just run a separate hot to the lights?

Now that my car is getting old, almost paid off and warranty almost gone I might as well have fun with it... :grin:
You would need a switch since it would always be on even if you used the dome loght ground and positive.
 

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Discussion Starter · #11 ·
Ok, so let me get this straight...

Red is power.
Black is ON ground.
Blue is the dimmer (DOOR) ground.

But if you splice the Blue, then it's constant 12v, until it reaches the switch, at which point the SWITCH chooses if/when it should dim? I would just think that the BCM would give the Blue wire the proper current when the door is opened instead of the switch deciding.

Not talking down to you, but did you try tapping straight off the Blue wire at first, and found that it didn't work properly that way, or is it just an educated guess?

Because I would think that there would have to be a difference between the 12v constant power and the blue dimmer wire power, right? If they were both 12v constant, then how would the switch know when to dim?
 

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The blue wire is connected directly to the BCM so it's hard to tell how and what makes it work. The BCM gets a signal from the door switches. Here's how I think it works (but I could be wrong). Whe you open the door, the BCM gets a signal from the door switch, turning the lights on. When you shut the door, the BCM loses the signal from the door switch and it gradually reduces voltage until the light is off. Im my car, I have LEDs and when the dome light is set to door, they are always very dimly lit, meaning the blue wire is always grounded but does some funky things. Hyundai does things a bit differently in their cars. In their case, all the switches and a few electronic modules are located on the grounded side of the circuits, as opposed to being on the positive side.

If you were to use the blue wire to connect your courtesy lights, it should work and dim but if you use it to ground the map lights, I really don't know how the BCM would react. The bulbs in the dome light and overhead console (if equipped) all use two grounds. One for the ON position and one for that goes to the BCM. It could kill the BCM or do nothing. I'm not willing to make a call on that.

I did try to tap directly to it but I did it in series, not in parallel so it didn't affect how it worked.
 

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Discussion Starter · #13 ·
Oh ok, I think I get what you're saying... I'll try to tap it straight from the Blue wire and see what magic happens. Hopefully nothing bad. Maybe I'll tap in a cheap LED strip to it first to test, just to make sure nothing breaks (i.e. my expensive mirror lol). I can't imagine the BCM would break if you tapped in one more thing... hopefully not anyway. That would be $$$.
 

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Last time I did a project like this was on a Chevy...  Thought I would tap into the 12v to the dome light and ground the lights to the body. They never went out...  Ended up finding that the 12v is constant but the ground is switched and apparently was pulsed as the lights faded out.  Appeared to use pulse width modulation on the ground side to switch off and on so rapidly that you can't see the flicker but it gives the human eye the impression that the light is dimming.  Not sure if that's how Hyundai sets these things up.  Hate to blow up the BCM finding out. :grin:
 

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Discussion Starter · #15 ·
The 12v IS constant.. the ground wire is what is going to control the dimming, unless Hyundai made the dome circuit differently than the fog light and horn circuits in this car. Hyundai uses opened and closed grounds to complete the circuits... the 12v is always constant in this car as far as I know.

With the assumption that this is the case for the dome light, then the only variable is still the dimming ground wire. If the BCM simply steadily lowers the voltage or whatever for the dimming ground wire, that would be awesome, because you could definitely hook the lights up directly (Map Lights 12v(+) to 12v constant dome light wire, Map Lights ground (-) to the Blue Dimming Wire (door))... if it kills the ground connection, there's no circuit = lights turn off. If it uses some crazy PWM, that might be a pain. I'm just really trying to NOT have to feed wires through the headliner... if there's an easier way, it'd be awesome haha.

I guess I just don't understand how the dimming ground wire (door) could possibly be constantly open and complete the circuit. If that were the case, then shouldn't the light be on all the time? Unless there's crazy circuitry IN the dome light switch itself that interprets the dimming ground signal and converts it to open and closed circuit...

Hmm... can't wait til I get a free afternoon to mess with this lol... hopefully it won't end up like my hacked-to-pieces fog light harness LOL
 

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QUOTE (bloodninja @ Nov 30 2010, 10:43 PM) index.php?act=findpost&pid=375983
The 12v IS constant.. the ground wire is what is going to control the dimming, unless Hyundai made the dome circuit differently than the fog light and horn circuits in this car. Hyundai uses opened and closed grounds to complete the circuits... the 12v is always constant in this car as far as I know.

With the assumption that this is the case for the dome light, then the only variable is still the dimming ground wire. If the BCM simply steadily lowers the voltage or whatever for the dimming ground wire, that would be awesome, because you could definitely hook the lights up directly (Map Lights 12v(+) to 12v constant dome light wire, Map Lights ground (-) to the Blue Dimming Wire (door))... if it kills the ground connection, there's no circuit = lights turn off. If it uses some crazy PWM, that might be a pain. I'm just really trying to NOT have to feed wires through the headliner... if there's an easier way, it'd be awesome haha.

I guess I just don't understand how the dimming ground wire (door) could possibly be constantly open and complete the circuit. If that were the case, then shouldn't the light be on all the time? Unless there's crazy circuitry IN the dome light switch itself that interprets the dimming ground signal and converts it to open and closed circuit...

Hmm... can't wait til I get a free afternoon to mess with this lol... hopefully it won't end up like my hacked-to-pieces fog light harness LOL
The BCM uses a signal from the door swith to start dimming the dome light. Otherwise, how would it know when you want the dome light off since 12V is constant? The dome light has no special circuitry, just some metal traces to the bulb and switch.
 

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Courtesy light wiring figured out. Now hardwired to work off the door jamb switch. The switches are ground activated. Meaning when door is opened, the switch grounds to complete the circuit.

Items used:
4 Pin relay
LED strips from Advance Auto
Wire and Connectors
Add-A-Fuse (mini)

Inside driver kick panel you will see the blue junction box shown in picture. On the right side of it there are two solid green wires plugged into the same slot. These are the door jamb switch grounds. Verified with multimeter.

Find where you want your lights, mount them and run all wires in the direction of the kick panel.

Get your relay and start connecting. Don't forget to disconnect the negative battery lead.

Pin 30 - Connect 12v constant power to this Pin. Use the Add-A-Fuse to connect to a constant 12v in the fuse box. I used the hazard light fuse.
Pin 85 - Tap into the door jamb switch grounds and run a short wire to this Pin.
Pin 86 - Jump 12v constant power from Pin 30 to this Pin.
Pin 87 - Connect your lights 12v positive line to this Pin.

Pins 86(12v constant) and 85(door switch ground) activate the relay by completing a circuit. When relay is activated Pins 30(12v constant) and 87(lights positive) connect and supply your lights with the needed power.

Ground your lights, right beside the junction box there are threaded holes already there. Just go through your junk draw and find one that fits.

Reconnect your negative battery lead.



Congrats your courtesy lights are now working off the door switches.
 

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Discussion Starter · #18 ·
Dude....... You are my hero. :trophy: Seriously.... Thank you so much. This will make my auto-dimming mirror install so clean! Maybe I'll even add some more interior door activated lights :D
 
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