My LED Lighting Project (2009 Yukon XL)

[agupta3224]

This project is three fold.

1. Add LED lighting to the running boards and under the rear bumper as Approach and Exit Lighting.​

2. Add LED lighting to foot wells and under the doors.​

a. Also add accent LED lights to doors.​

3. Add DL3 mirrors without changing any window switches. (This has been discussed in many threads in forums so I will just post pictures when done of my setup unless someone requests a write up).​

I will write this as I progress and if there is more interest.

1.

The outside lighting is a bit tricky. But here is the theory behind how I thought it would work. I grabbed three power sources (dome lighting, Accessory and Always on Battery Power). First things first, these lights are being powered by the Battery Power. We need a way to shut them off after a certain time and also make sure they never come on when the truck is on or is being driven.

I accomplished this by using two relays. Relay one is charged when the dome light is on and Relay two is charged when the Accessory Power is on (i.e. when the key is in I or II position). The difference is that relay one is a NO relay (normally open) and relay two is NC (Normally closed). The power goes from MBEC to Relay One, then to Relay Two and then to the outside lights. Whenever the Dome Light Turns on and the key is not in I or II position, the outside lights will turn on (Relay One will close since it being charged and Relay Two is always close). Once the key is switched to I or II position the outside lights will turn off (Relay Two is now open, stopping the flow of current to the outside). They will also turn off when the dome turns off (Relay One is now open). The advantage to this setup is, when driving if the dome is turned on the outside lights will stay off.

MBEC: Pinouts.

X9: Pin 8 is Dome Lighting. This is marked Courtesy Lights and is the Gray Wire.

X14: Pin 1 is Ground. Pin 2 is 15A Battery Out (always Hot). Pin 7 is Accessory (Switched Power)

Please pardon the crude diagrams and my writing.



Two relays mounted on the right side. Under the fuse panel cover.



Cannot really see the brightness, but it is very functional. I will post better pictures later.

So far that is all I have done. There is a lot of prep work involved as well.

Before anyone asks, I got the LEDs from a Building Sign. A shop sign fell off and the owner was going to throw it away. I happen to pass by and asked the owner if I could take it, and he said yes. So the LEDs are prewired for 12V and are commercial grade (Made in USA).

One more thing. I am using a lot of wire, so I bought a Trailer Wiring Package from Harbor Freight. There are 5 different color 14 gauge wire and each measures 25 feet. Comes with some Wire taps and wire nuts as well.

 

[yugrus]

Why did you not go with just one relay that is powered by the dome light (X9 P8)? It goes out when the engine is started anyway?
The dome light has a reverse dimmer, where it gradually builds up voltage at lights via pulse modulation. Does your first relay not making an awful rattle when the lights go on?

 

[agupta3224]

Why did you not go with just one relay that is powered by the dome light (X9 P8)? It goes out when the engine is started anyway?
The dome light has a reverse dimmer, where it gradually builds up voltage at lights via pulse modulation. Does your first relay not making an awful rattle when the lights go on?

Hello,

The reason for the second relay was to make sure that the lights outside do not turn ON when the dome is on and the SUV is running. I like the dimming effect but I do have little kids and they do drop stuff and hear.... "Papa, PLease turn on the light." So if I turn on the light and I am driving, I do not want the outside lights turned on.

 

[yugrus]

When you turn individual light on in the cabin, it has no effect on X9 junction... Turn it on as much as you want, your puddle lights will not do the same.
So, does your relay make a rattle?

Sent from my VIVO XL using Tapatalk

 

[agupta3224]

Got a little bit more done.

I was able to install accent leds in one of the door panels.
When I ordered the LED the light was quite focused. To scatter/diffuse the light I sanded the LEDs using a Rotary Tool. Washed the sanded LEDs in running water and dried. You will see that I used a black marker on half LED. This hald will be pointed outwards. So if I am driving I really do not want to see the LED in the Passenger door.

Once again my apologioes, this project is very slow.


Inside of the door. The leds are 5mm, which is 13/64 drill bit. This is not wired yet but the lighting is supposed to be accent only.

These are the leds from the outside.


Red Circle - Original LED
Yellow - Sanded LED
Blue and Black - Colored with Marker

Also got a dimmer with a remote control. Ebay ($3). 10% brightness is the best accent when lit.
As I said I am not trying to overwhelm the inside, just a little blue accent.

Comment as you see fit. I appreciate all feedback.

 

[agupta3224]

When you turn individual light on in the cabin, it has no effect on X9 junction... Turn it on as much as you want, your puddle lights will not do the same.
So, does your relay make a rattle?

Sent from my VIVO XL using Tapatalk

I did not know that. No there is no rattle on the relay. It is good to know. When I was testing it I was able to turn the X9 junction off and on with the dome switch. So I was thinking that X9 turns on whenever the dome is on.

 

[yugrus]

When I was testing my puddle light prototype, similar to yours in terms of LED placement, the straight relay hooked to X9 was rattling, which was expected given the nature of the gradual voltage build-up in the dome light. So I went with common collector cirquit with power transistor that is fed from the constant power source and controlled by the dome light power at X9. That gave me the gradual build-up of light in foot wells and outside at puddle lights. This arrangement has a draw - back of somewhat reduced voltage at LEDs, so they are not as bright as they should be, although plenty bright. Next iteration is a voltage comparator that kicks in when the dome light is fully powered by the BCM. Next spring, I guess...
Use individual switches for dome lights on the go, X9 will not be affected.

 

[agupta3224]

When I was testing my puddle light prototype, similar to yours in terms of LED placement, the straight relay hooked to X9 was rattling, which was expected given the nature of the gradual voltage build-up in the dome light. So I went with common collector cirquit with power transistor that is fed from the constant power source and controlled by the dome light power at X9. That gave me the gradual build-up of light in foot wells and outside at puddle lights. This arrangement has a draw - back of somewhat reduced voltage at LEDs, so they are not as bright as they should be, although plenty bright. Next iteration is a voltage comparator that kicks in when the dome light is fully powered by the BCM. Next spring, I guess...
Use individual switches for dome lights on the go, X9 will not be affected.

Thank you. I will keep that in mind. As far as I have tested it, just the footwell lighting, it dims off with the dome lights. I did not hear any rattle. When I tested the outside lighting, it worked fine as well. I will try to listen more next time I power it up. I am trying not to put too much draw on X9. So I am keeping the inside only on X9. I have already converted all the interior lights to LEDs so there should not be a big draw. This is a big project, I am also converting my DL8 to DL3 as well. I did not buy any switches for that conversion. I will install my own switches, realys and timers. Hopefully it will work good.

 

[agupta3224]

Here is the Accent lighting. It is at 10% brightness.


Here it is at 25% brightness.


The pictures do not do justice. It looks much nicer actually.

Once again the idea is accenting not to overwhelm.
With the remote, I could increase the brightness to the level I want.
Once again comments are welcome.

 

[ddubdb3]

Nice write up!! Your doing the same exact project I'm doing as well. So far I've just added puddle lights and footwell lights. The Opt 7 footwell led kit I highly suggest looking into. For my puddle lights I just tapped into the dome lights down under the dash so the lights gradually dim out same as the dome lights and keeps the install simple.