vulcan_classic

There in order from left to right looking at it fro bottom, the last is grey X7

I decided to rewire them to the license plate lights signal since the dimmer circuit is a PWM signal and the leds weren't getting full 12VDC. This works better since they get 12VDC and full brightness and come on automatically whenever running lights are on, connect to BCM connector X4-13, GRN/YEL wire

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

FYI Here is tailights schematics (MY2020) for anyone interested; use the RPO codes which match your trim level: tailights.pdf

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.

Coming from a ZR2 with the duratracs, there's no comparison with ride quality; the 20" Bridgestone Duelers are amazingly quieter and smoother ride for me at least, and are also nominally a 33" tire, 275/60-20 vs. the 275/65-18 duratracs (32"). I'll eventually move to a 34 or 35 tire size and maybe add spacers for a wider stance, but I'm really enjoying the ride quality compared to my ZR2. May even consider powder coating the stock 20" wheels all black.

Cool but thats not the dimmer circuit

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

if you hold the start button about 10 seconds it will turn everything on like turning a key on without starting the engine. Not sure how long it will remain on though, worth a try. Of course you'll need to leave FOB in the vehicle.

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

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!

I made some rubber standoffs out of hard rubber hollow tubing and some 3/8” hardware, just stuff I had laying around. 3.5-4” long bolts and some nuts and washers to anchor to the bedside knockouts, slip the rubber standoff over the bolt and tighten down, mount the jack and then add another set of washers and nuts on each to lock it down. Sent from my iPhone using Tapatalk

Mounted Hi-Lift jack on bed wall. Sent from my iPhone using Tapatalk

Yes Satin Steel Metallic Sent from my iPhone using Tapatalk