Footwell lights 2022 refresh Silverado

RedLT · September 29, 2022

11 hours ago, matt99199 said:

That 7.5V that you measured was probably a PWM signal from the BCM to the dome light directly. Would need an oscilloscope to confirm.

I'm trying to confirm for the refresh models now in my post here (for anyone interested):

I'll be able to figure it out soon as I have contacts inside GM and also at the dealership.

Thanks Matt! Keep us posted. LOL, I was going to link your thread over here as well.

paauto · December 28, 2022

I'm in the process of installing footwell lights. On my 2017 I used the following relay, which allows for an adjustable "off time". I initially used a standard relay, but it pulsated on and off due to the PWM feed off the BCM. The Beular relay fixed this by holding the relay on for 5 seconds. It only requires 8 volts to trigger. Going to try this on my 2023 Sierra...

https://www.qualitymobilevideo.com/bu510td.html?gclid=CjwKCAiAzKqdBhAnEiwAePEjkqSzrm9emtUhz0gqI-MJDodizLSS_FPZAVijfTnmT94-Gocj82c8jRoCC-QQAvD_BwE

Edited December 28, 2022 by paauto
fixed typo

LowUfo · December 28, 2022

14 hours ago, paauto said:

I'm in the process of installing footwell lights. On my 2017 is used the following relay, which allows for an adjustable "off time". I initially used a standard relay, but it pulsated on and off due to the PWM feed off the BCM. The Beular relay fixed this by holding the relay on for 5 seconds. It only requires 8 volts to trigger. Going to try this on my 2023 Sierra...

https://www.qualitymobilevideo.com/bu510td.html?gclid=CjwKCAiAzKqdBhAnEiwAePEjkqSzrm9emtUhz0gqI-MJDodizLSS_FPZAVijfTnmT94-Gocj82c8jRoCC-QQAvD_BwE

Would you use the BU510TD which is a Time Delay ON relay, or would you use the BU509TD which is a Time Delay OFF relay? Where does the trigger wire connect to?

Edited December 28, 2022 by LowUfo

paauto · December 29, 2022

You'll want to use the "Delay-Off" version.

For my 2023, I am hooking the trigger up to Pin 23 on the first plug (X1) on the BCM. This controls the "Dome Lights". The wire color is gray. In the 2023 up fitter manual, you can find it on page 6-308. PM me if you want me to send you the manual. I'm still in the process of installing. I put the lights in today (for the back row, I put them at the bottom of the B pillar and for the front I put them at the top of the kick panel.

On my 2017 I installed footwell lights and tapped into the equivalent pin as above. At first I used a standard relay. I learned, though, that the dome lights "fade" off. The BCM uses PWM (pulse wave modulation) to accomplish this. Essentially, it rapidly cycles the circuit on & off at varying frequency to dim the lights to the off state. A standard relay will turn on & off as the PWM kicks in, essentially flashing the footwell lights on and off.

The Bueler delay off relay provides for a delay once the trigger power (i.e., the dome light PWM circuit) starts to fade to off. Even a 5 second delay will "ignore" the PWM issue described above with a standard relay.

Hope this helps.

LowUfo · December 30, 2022

23 hours ago, paauto said:

You'll want to use the "Delay-Off" version.

For my 2023, I am hooking the trigger up to Pin 23 on the first plug (X1) on the BCM. This controls the "Dome Lights". The wire color is gray. In the 2023 up fitter manual, you can find it on page 6-308. PM me if you want me to send you the manual. I'm still in the process of installing. I put the lights in today (for the back row, I put them at the bottom of the B pillar and for the front I put them at the top of the kick panel.

On my 2017 I installed footwell lights and tapped into the equivalent pin as above. At first I used a standard relay. I learned, though, that the dome lights "fade" off. The BCM uses PWM (pulse wave modulation) to accomplish this. Essentially, it rapidly cycles the circuit on & off at varying frequency to dim the lights to the off state. A standard relay will turn on & off as the PWM kicks in, essentially flashing the footwell lights on and off.

The Bueler delay off relay provides for a delay once the trigger power (i.e., the dome light PWM circuit) starts to fade to off. Even a 5 second delay will "ignore" the PWM issue described above with a standard relay.

Hope this helps.

I see Pin 23, X1 on BCM is "Interior Lamp Control" for the 2500HD/3500HD trucks. I've looked at the manual for the 1500 series (2023). I could not find "Interior Lamp Control", but did find "Done/Reading Lamp Enable Signal" on pin 3 of X3. Can anyone confirm if this pin will work for footwell lights? Thanx

paauto · December 31, 2022

I think that should work. That's circuit 4786. Check out page 2-32 for the schematic.

I looked thru all the BCM plugs and don't see anything more specific for the dome lights.

Let us know!

Geo9455 · February 11, 2023

Hello, slightly confused and not sure if this was resolved. I have a refresh 22 Sierra and would like to add some footwell lighting and need a trigger source.

Minmax · February 11, 2023

I have given up for the time being. Hoping someone comes up with a module or some sort of sure fire work around. I may install the set I have and install a separate switch somewhere to access them… but would rather they worked the way my old 2017 Canyon did, which was, they worked exactly how the ceiling lights worked, and they were fantastic.

LowUfo · February 11, 2023

11 hours ago, Geo9455 said:

Hello, slightly confused and not sure if this was resolved. I have a refresh 22 Sierra and would like to add some footwell lighting and need a trigger source.

I'm still waiting for my new truck to show up! It's been on order for almost 4.5 months and still not here. I've been researching. Check the above posts from paauto and see if pin 3 of X3 works. From his help, it looks like pin 3 of X3 seems to be the best trigger point. I have already purchased the Bueler Time Delay OFF relay. Paauto has an HD truck - it seems easy to connect footwell lights. Once my truck arrives, and I get to try a few things out - I'll let everyone know and I'll take some photos as well.

Firetiger(MN) · February 12, 2023

On 2/11/2023 at 7:58 AM, LowUfo said:

I'm still waiting for my new truck to show up! It's been on order for almost 4.5 months and still not here. I've been researching. Check the above posts from paauto and see if pin 3 of X3 works. From his help, it looks like pin 3 of X3 seems to be the best trigger point. I have already purchased the Bueler Time Delay OFF relay. Paauto has an HD truck - it seems easy to connect footwell lights. Once my truck arrives, and I get to try a few things out - I'll let everyone know and I'll take some photos as well.

The wiring on the "refresh" models appears to be different and I would suggest not copying what the OP did, as he has an older truck.

I looked over the schematics and it appears they are sending a data signal to the overhead module rather than switching the power on/off from the BCM under the dash like they did in the pre-refresh years. The module in the overhead then does the power switching to the dome lights. Maybe I'm not interpreting the schematics correctly, but that's how I'm seeing it.

LowUfo · February 12, 2023

24 minutes ago, Firetiger(MN) said:

The wiring on the "refresh" models appears to be different and I would suggest not copying what the OP did, as he has an older truck.

I looked over the schematics and it appears they are sending a data signal to the overhead module rather than switching the power on/off from the BCM under the dash like they did in the pre-refresh years. The module in the overhead then does the power switching to the dome lights. Maybe I'm not interpreting the schematics correctly, but that's how I'm seeing it.

It definitely is not as easy as on my 2016! When the truck comes in, I'll try some things. Worst case - I'll add a relay and switch

Razorback7 · February 15, 2023

So the illuminated door sills for the refreshed trucks use "cavity #1" on the X1 BCM connector to power the door sills. Would that work for footwell lighting as well? See pages 17-18.

2022-sill plate.pdf

Minmax · February 15, 2023

I’m curious now. I’m sure it would work to at least power on floor lamps when the doors open, which is awesome, but I want them to come on with the “all domes” button as well. Not sure if it would come on in that instance. I suppose when I feel up to it I’ll have to get the old meter out there and try messing with it.

LowUfo · February 15, 2023

When you look at Page 7-363 of 2023 Sierra 1500 Electrical Body Builder Manual, Pin 1 of K9 Body Control Module X1 - it shows "not occupied"

Jglew82 · February 19, 2023

I installed AMP Research steps on my 23 yesterday. When installing the OBD2 plug, there are 2 wires that connect to 2 different BCM plugs for the lights. These might just be door trigger inputs, but might be a step in the direction you’re looking for. I didn’t test them when installing for voltage.