Tying in the Mirror Task Lights to gain more functionality.

[Will Jenkins]

Has anyone been able to modify the task lights to gain more functionality from them? I am currently running boost auto parts' spot light with high beams harness but I wanted to get more use out of them. From the factory they are basically useless as they can only be used in park. 

 

Does anyone know how they could be tied into the puddle lights so that when the truck is unlocked or remote started they come on like perimeter lights? Could this be done with a one way diode? Could they be tied into the turn signals? 

 

This was quoted from a thread a couple months ago by a user with the name kodiakdenail however, i'm not sure what is possible. 

 

Both task light signals are +12V signals, so you can use a diode to tie them together.

the puddle lights are controlled by the BCM connector X7, pin 8, GRY/GRN wire, this puts +12V directly to the lower puddle light LEDs in the mirrors.

the exterior cargo lights and interior cargo lights (bed lights) are controlled independently.

exterior cargo lights are activated by a relay which is  controlled by BCM connector X6, pin 26, BRN/WHT wire

even though this wire is a relay control, it looks like it controls the relay with 12V and not ground like is usually the case. the schematics clearly show the relay coil getting one signal from the BCM, the other side is tied to ground.

since the only thing that you would be adding to the puddle lights circuit is a simple relay control, you likely can do this just with a diode, you won't be adding much load at all.

 

so...theoretically:

 

A FORWARD biased diode between X7 (gray connector), pin 8 (GRY/GRN) and X6 (pink connector), pin 26 (BRN/WHT) should activate the exterior cargo lights (high mount cargo light and the "hitch" light on the tailgate, but not the bed lights) any time the puddle lights are on. Forward biased means the stripe on the diode should go towards the X6 pin 26 BRN/WHT wire.

 

for reference if you look at the upfitter manual:

BCM pinout for the puddle lights (BCM connector X7) is on page 7-257 ***note that for some reason the schematic seems to use the term "puddle lights" to refer both to the puddle lights and the task lights, they are not the same, but the manual uses the same name. no idea why, verify this with the schematic page referenced below)

BCM pinout for the cargo lights relay control (BCM connector X6) is on page 7-256 ***note the manual for some reason refers to the cargo light relay as the "standing lamp relay control" which again, you can verify this is the correct wire on the schematic referenced below

the puddle lights schematic is on page 2-35. which shows the puddle lights connected together (left and right) powered by positive voltage from the BCM, X7 pin 8. You can also see the task lights on this schematic. I don't know why the naming inconsistency, but the BCM pinout calls both lights "puddle lights" the schematic uses the terms flood lights lower and flood lights forward for the puddle lights and task lights respectively. at least I think I don't know what else those could possibly be.

cargo lights schematic is on page 2-38, which shows the cargo lamp relay controlled by BCM X6 pin 26 (which the BCM pinout refers to as "standing lamp relay" for some reason)

 

[redwngr]

Fwiw, the cargo and tow mirror lights on my '21 Denali work in neutral, reverse and park. 

 

EDIT: 

I may have mis-understood thread's question

 

These are the rear-facing back-up led's in mirror's that come on when the cargo light button is used.

 

 

 

I never use the lights activated by the 'task' light button

Edited September 22, 2022 by redwngr