Adding 12v to back end of 23 Yukon Denali

[BobHolthaus]

My girlfriend took delivery of her 2023 Denali Duramax 2 weeks ago and I am shocked that there is no 12v outlet in the cargo area. We both run ARB Fridges in our vehicles; can someone point me to a thread or tell me the easiest way to route wiring back there for an outlet? I’m a Jeep guy, so I can wire just about anything (I own a low voltage company). But I’d love some advice on where to run wiring and if there is anywhere to tap 12v constant other than the battery. Thanks in advance.

 

[Doubeleive]

does it have a tow package? if so there is 12v right there, might have to connect the wire up front under the hood typically in the past generations it's bundled up somewhere near the fuse box or battery and connects to a post/terminal. if you can't find it swing by any trailer store that installs tow packages they should know right where it is.

once you patch into 12v you should be able to remove a tail light housing and run it inside from behind the tail light

 

[Mean_Green]

^^^ I did that on my '98. Used the 12V from the tow harness, drilled a small hole in the floor under the left compartment where the jack is stowed and put a 4 terminal fuse block in there.

 

[BobHolthaus]

Ah yes, this is why I lean into these forums! The 12v from the tow package is a great idea, and it should be independently fused as well. Thank you guys. I’ll try to figure it out and post back here when I’m finished.

 

[BobHolthaus]

I will verify this with my 12v tester, but based upon the owners manual, this should be fuse 84.

 

[BobHolthaus]

Also, can anyone point me to a thread about removing the rear side panels so that I can flush mount an outlet? TIA.

 

[StephenPT]

Here's the Body Builder Manual for your rig - lots of helpful info in here regarding wiring diagrams, functions, etc.

https://www.gmupfitter.com/wp-content/uploads/2022/09/23_Yukon_Yukon_XL_Electrical_Body_Builder_SM_en_US_092822.pdf

As far as removing a side panel - it's a pretty big job to completely remove the panel as you have to unbolt the end of the seatbelt from the floor and push it back through the panel to then remove the panel. You can however loosen the panel quite a bit and get decent access to the backside of it.

First remove the rear cargo sill. It's held down by metal clips, so you'll need a plastic trim tool to pry at a corner and once a couple of the clips release you can keep pulling to remove it completely. Next, lift the cargo compartment lid and you'll see four large plastic nuts holding the compartment to the floor. Remove those nuts and then the compartment lifts right out of the rig.

Next, remove the D-Pillar plastic trim. The first piece without the speaker grille needs to come off and then the piece with the speaker grille is held on by one 7mm head screw and a few metal clips. With that trim removed, take off the plastic nut used for the cargo net and below it the metal D-ring. Now you'll have access to pull the side panel away from the sidewall and have access to the backside. Good luck!

 

[BobHolthaus]

Here's the Body Builder Manual for your rig - lots of helpful info in here regarding wiring diagrams, functions, etc.

https://www.gmupfitter.com/wp-content/uploads/2022/09/23_Yukon_Yukon_XL_Electrical_Body_Builder_SM_en_US_092822.pdf

As far as removing a side panel - it's a pretty big job to completely remove the panel as you have to unbolt the end of the seatbelt from the floor and push it back through the panel to then remove the panel. You can however loosen the panel quite a bit and get decent access to the backside of it.

First remove the rear cargo sill. It's held down by metal clips, so you'll need a plastic trim tool to pry at a corner and once a couple of the clips release you can keep pulling to remove it completely. Next, lift the cargo compartment lid and you'll see four large plastic nuts holding the compartment to the floor. Remove those nuts and then the compartment lifts right out of the rig.

Next, remove the D-Pillar plastic trim. The first piece without the speaker grille needs to come off and then the piece with the speaker grille is held on by one 7mm head screw and a few metal clips. With that trim removed, take off the plastic nut used for the cargo net and below it the metal D-ring. Now you'll have access to pull the side panel away from the sidewall and have access to the backside. Good luck!

Wow, this does seem like quite a project. Thank you for the PDF; I looked at the trailering section and am immediately reminded that every wire on these things seems to run through the CANBUS system (or whatever GMC calls it). It says the trailer battery connector is "constant" (page 2-60), but that the vehicle may not allow certain accessories to function. It would be a shame if the car was so "smart" that it turned off the circuit to my 12v outlet, which would be powering the ARB Fridge unit. I am quickly thinking that it may be in my best interest to run an appropriate wire directly to the battery that cannot be shut off accidentally. THIS is the kit I have used in the past on my Jeeps.

 

[BobHolthaus]

Okay, after looking at the backend tonight, I didn’t realize there was a fuse box behind a panel on the driver side. That allows me to reach my hand up and touch the plastic above it. I am going to install Two 12 V outlets facing up back there, one which will be a regular outlet and the other one will be an ARB locking outlet. I bought THIS wiring kit from ARB and will drill a hole down in the bottom of that cubby near the bottom of the jack and will run the wire up underneath the car all the way to the battery. It should be very simple. I will post pics when I’m finished.

 

[Mean_Green]

'You'll put your battery out with that thing!!'

Be careful that whatever you plug in back there doesn't have the ability to run your battery down. Most stock things are run through some sort of timer that kills power after a few minutes.

.