Dimmable footwell lighting

[vulcan_classic]

Ok so I started to dig into this and it looks like the only way to tie into the factory wiring is to connect to the BCM dimmer circuit. Based on the 2020 GM upfitter electrical drawings, I may be able to connect the front lights to the dimmer circuit behind the center stack switches, and the rears to the dimmer circuit behind the rear console USB /Aux connectors.

 

The dimmer circuit is designated circuit  # 6817 on the drawings and is YEL wiring. This is most likely a PWM signal since it is variable and controlled by the dimmer controls to the left of the steering wheel at the light switches.

I had success doing this on my 2017 ZR2 using LED strips placed under the dash on both sides and under the rear of the front seats using velcro.

 

First step is to gain access to the center stack without destroying my dash trim! For anyone wanting to do footwell lights operating off the dome lights its almost impossible the way GM has redesigned the dome lights to be controlled from the BCM via the interface logic boards at the lamps in head liner. However, the courtesy function (dome lights and footwell lioghts) will still work but only when driver door is opened, based on how things work in my loaded 2020 AT4. Otherwise any other door opening will onlt turn on the dome lights, unless disabled by the local switch at the overhead lamp location.

 

Stay tuned!

Edited March 14, 2020 by vulcan_classic

[vulcan_classic]

hers a link to the drawings from GM Upfitters, excellent info source!

 

Electrical:

https://www.gmupfitter.com/files/media/photo/1290/20_Sierra_1500_Electrical_Body_Builder_2019JUN20.pdf

 

Chassis:

https://www.gmupfitter.com/files/media/photo/1372/R_2020_LD_FS_CK_PU_01_06_2020 (1).pdf

 

 

[vulcan_classic]

looks like the easiest way to make this connection is at the BCM on the X7 grey connector pin 9.

[ArTurf]

Just added footwell lights using this wire, tapped wire with Posi-tap connectors, easy

 

 

[vulcan_classic]

Cool but thats not the dimmer circuit

[ArTurf]

I have to ask why do they need dimming  if you select lights of the correct brightness to begin with

[vulcan_classic]

I want both functions, i.e. dimmer function and nightlighting, i dont see how it would work connecting to the dome lights circuit, i dont drive around with my dome lights on. With the dimmer circuit they will come on with dome lights via the BCM whenever the driver door opens or if you turn on your running lights (instrument backlighting) I have always wired footwell lighting in this way on numerous vehicles.

Edited March 19, 2020 by vulcan_classic

[2k19Sierra]

Wired mine into the aux switches. Nice to have a factory switch to turn em on and off. Use the remote to set the colour and brightness. 

[Limelight]

I did it like this on my 2500HD...not accent lights, they work like the O/H lights...  A few posts down I replaced the strip lights with better Pod lights that match the factory lighting,  Big difference at night!

 

https://www.gm-trucks.com/forums/topic/236284-footwell-lights/?do=findComment&comment=2391900

[PearlyWh1tes]

Just did it today, wired it to the grey wire(the one not in the corner of the connector) connected to the door sensors on the white connector of the bcm, the lights come on when I open any door, and all for $25. As for dimming, you can wire in a potentiometer/dimmer switch directly into the loop of the lights wiring right before the first light if you really want the option.

Edited April 1, 2020 by PearlyWh1tes

[PearlyWh1tes]

On 3/19/2020 at 8:12 AM, vulcan_classic said:

I want both functions, i.e. dimmer function and nightlighting, i dont see how it would work connecting to the dome lights circuit, i dont drive around with my dome lights on. With the dimmer circuit they will come on with dome lights via the BCM whenever the driver door opens or if you turn on your running lights (instrument backlighting) I have always wired footwell lighting in this way on numerous vehicles.

Wire it to the bcm and add in a potentiometer/dimmer switch before the first light

[vulcan_classic]

On 4/1/2020 at 12:12 AM, PearlyWh1tes said:

Wire it to the bcm and add in a potentiometer/dimmer switch before the first light

I actually wired them as i mentioned previously, YEL wire (#6817) on pin 9 of BCM connector X7, works perfectly, the LED's can be dimmed with the dimmer +/- buttons whenever the instrument back lights are on, and they also come on automatically with driver door opening

[Likarok]

These might also make good footwell lights!

 

https://accessories.chevrolet.com/product/exterior/outside-rearview-mirror-puddle-light-kit-with-bowtie-logo-projection-(for-models-with-heated-outside-rearview-power-adjustable-mirrors)-84408372?year=2020&make=Chevrolet&model=Silverado 1500&modelId=491&body=Crew Cab Pickup&bodyId=22&wheel=Short Box&wheelId=651&trim=High Country&trimId=523&drive=4WD&driveId=8&engine=3.0L L6 DIESEL&engineId=17881&bodyNumDoors=5&categoryId=12002

[ausomecasey]

On 4/10/2020 at 2:05 PM, Likarok said:

These might also make good footwell lights!

 

https://accessories.chevrolet.com/product/exterior/outside-rearview-mirror-puddle-light-kit-with-bowtie-logo-projection-(for-models-with-heated-outside-rearview-power-adjustable-mirrors)-84408372?year=2020&make=Chevrolet&model=Silverado 1500&modelId=491&body=Crew Cab Pickup&bodyId=22&wheel=Short Box&wheelId=651&trim=High Country&trimId=523&drive=4WD&driveId=8&engine=3.0L L6 DIESEL&engineId=17881&bodyNumDoors=5&categoryId=12002

Cool, is that a new GM accessory?

[Rubyralph]

On ‎4‎/‎7‎/‎2020 at 12:47 PM, vulcan_classic said:

I actually wired them as i mentioned previously, YEL wire (#6817) on pin 9 of BCM connector X7, works perfectly, the LED's can be dimmed with the dimmer +/- buttons whenever the instrument back lights are on, and they also come on automatically with driver door opening

Can you please take a picture to show where the yellow wire is located?

I want my led foot well lights to stay on while driving at night and when I open the doors, this sounds like this would do the trick?!

Thanks Ralph