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Let's install the "upfitter switches"

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This week, I'll slowly detail the installation of the GM upfitter switches. They're going in a 2020 GMC Sierra AT4.


If you're not familiar with the Upfitter Switches, they're a bank of 5 switches for controlling whatever you want to add (snowplow stuff, external lights, compressors, etc). They are/were orderable from the factory, in fact my truck came with them. Google is your friend...


Unfortunately, neither the factory  nor the dealer (generally) install the upfitter switches for you. As a matter of fact, my window sticker says "UPFITTER SWITCHES(5) CUSTOMER RESPONSIBLE FOR INSTALLATION"  This means you'll be installing the switches yourself. Honestly it seems like no big deal... but I find the instructions confusing, so I thought I'd document my installation for others.


The switches themselves are just to the left of the steering wheel, on the kick panel. This part was already installed in my truck. If you are adding the upfitter switches to your truck, you may have to purchase the kickpanel and switches separately from the kit.


The kit includes three main parts: A set of fuses and bolts to connect to the secondary battery, a long extension cable for the power, and a fuse block that gets installed behind the switch kickpanel in the cab.


So..... This week I'm going to slowly install the kit. I'll take pix and try and explain what I'm doing. Feel free to ask questions, etc.


First, start here: https://www.gmupfitter.com/pages/technical-bulletins

Search for your vehicle (in my case it's a 2020 C/K 3500HD). 

You should find a PDF that lists the instructions there somewhere.


I'll try and come up with part numbers as I go. The option itself is called 9L7.


Don't Forget - if you're ordering this kit separately, because it didn't come with your truck, you'll need not only the three main parts above, but the switches themselves, and the replacement kick panel, neither of which come as part of the kit.


Edited by blamkin86
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Thanks for doing this!  I may end up having to do this if my dealership ends up refusing to do this as they have said in the past they will.  I ordered our AT4 3500 with the Upfitter Switches in Dec and it was built 1 Feb.  Truck, as of last Friday, is still sitting in Flint waiting to be put on a rail car!

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OK - first a stern warning. 


This installation isn't exactly for the faint of heart. You'll be taking apart your dash, maybe more than some would like. 


Also, when you'r working under the hood, be CERTAIN that you place your phone somewhere it won't fall into the engine bay. I wasted 20 minutes fishing mine out from UNDER the intercooler.


Finally, I did not install the kickpanel or switches themselves into my truck - they were already there. If you have to replace your kickpanel with a new one with the switches, my guide does not list these steps.


You have been warned!

Edited by blamkin86
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Before I start, I want you to go find the parts for this thing. BESIDES the switches and kick panel, you should have


1) A long 10-ga wire that's wrapped with foil heat protection. 

2) An electrical box with several connectors, and several fuses and relays inside

3) A pink bag containing studs, bolts, big fuses, metal plates, and very importantly a black plastic connector with no wires.


Also, reading through the directions, my kit is missing two items:

1) Several plastic clips to replace factory ones under the hood

2) Two small hex-head screws to attach the electrical box under the kick panel.


You can get away without the clips- you're going to need the screws or a replacement (which is what I'll do).

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I'm going to tackle this in three steps:


1) Installing the 10-ga wire from the passenger battery thru the firewall

2) Installing the electrical box under the kickpanel

3) Connecting the 10-ga wire to the passenger battery

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First up! The 10-ga wire. This wire will power the switches and a few amps for each switch to whatever you want to power.


It routes power from the battery on the passenger side, across the top of the firewall, through a special grommet in the firewall, to the new electrical box under the kickpanel that you haven't installed yet.


In this picture, you'll see the end of the wire that  you're going to shove through a special grommet in the firewall


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In this picture, you see the oil filler cap and the brake reservoir. This is the camera pointing back at the firewall right in front of the driver.




Reaching back between those two, the firewall has a large bundle of wires coming out of it. The wires go through a special grommet, that has an extra little tab on it.




You can see that tab on the bottom there. You're going to cut the end of that tab off so you can jam the wire in there. I tried to use scissors first, then a razor blade. I gave up and went with side cutters and they worked great. Either remove the end with the side cutters, or make a slit large enough to push in the end of the wire from the first pic.





Edited by blamkin86
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OK now you're going to run the wire across the top of the firewall. This part of the wire has silver heat wrap on it.


Mine also had 4-5 "loops" that help you secure the wire to the firewall.


Using great care, separate the plastic tabs already on your upper firewall from the firewall itself.  The picture shows how to lift the little tab on the top of main tab. When you do this (DON'T CUT IT JUST LIFT) the main tab will come all the way out of the upper firewall.



When you're done, the wire will be running across the engine bay, drooping over the passenger battery, and hanging out there where you cut the grommet behind the oil filler cap - like this:



(Note that I left off the last grommet by the battery - I will do that last - assuming I remember!)

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Now you're going to finish pushing the wire into the cab through the grommet you cut ealier.


This is a frustrating step - hang in there you'll get it.


Push the end of the wire into the grommet you cut. You won't get very far, because there's some foam on the other side blocking you. 

Unfortunately you're going to have to push as much as you can until it stops - other wise you won't be able to reach it from the inside.


Now, open the door, get on the floorboard and look up:




This is looking up, and to the right, of the steering column where it goes through the firewall. Where I'm pointing there, that's where the wire should come through. 


I had to go back and forth several times, fishing for the wire with my fingers, pushing from the engine bay side, until I got my fingers on the wire. You may find it easier to do this with some help, but I managed. I had to pull the foam out of the way, then go back to the engine bay, push the wire, blah blah, until I got enough to pull it through.


Once you get it through, route it above the heater outlet, and point it towards the parking brake control - this picture is looking straight up from the floor.




Finally, don't close off the firewall opening yet. Unfortunately, whatever you're going to wire to this switch ALSO has to come through that same opening you made for the power wire. (Which sucks- they should have put this next bit under the hood!)


Edited by blamkin86
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That's it for today. Neither end of the main wire is connected to anything - and that's ok for now.


Tomorrow we'll start discombobulating the dash. There are a lot of pieces to remove. If you feel overwhelmed by what you saw today, you'll never make it through tomorrow. 


Stay tuned!

Edited by blamkin86
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OK so today, we're going to finish the second phase of this project: the fusebox installation.


In short, we'll be:

1) Taking the kickpanel, side fusebox, and driver's side air vent loose or off.

2) Installing the black fusebox, just below the steering column behind the kickpanel

3) Connecting all the wires to the fusebox

4) and of course, putting it all back together.


You'll need a 7mm socket, I also used a 1/4" drive screwdriver AND ratchet

And you'll need an M15 torx bit. 


I'll tell you up front - my kit was missing some screws - you may have these - if not, you'll need to get some screws to finish.

What screws? Turns out they're the same size as the ones you're going to remove. 

I wound up repurposing two screws for the fusebox, and the two I'm missing are now on the outside so I can get them back on there some day.


Also, a warning here - you're going to be pulling the kickpanel loose at the bottom. This requires some force; I was able to get one side easily, the other side I wound up breaking and had to superglue back together. I'd imagine there's some tool, or at least some better method, to get the lower kickpanel loose but I'm not aware of that method.

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So this is a pic of the Upfitter Switches. You can see them down there on the left of the steering wheel. The panel they're on, I'm calling the kickpanel throughout. This is how my truck was delivered to me. As I said at the beginning, if your truck doesn't look like this, you'll need to remove your kickpanel when the time is right. I'll try and remember to mention it.




The next pix shows the approximate location of where the fuse box is going to be installed. It's basically centered under the steering wheel, but of course behind the kickpanel we're removing. 


I've taken off the fuse box cover so you can see that the fuses actually point down when you're done.  

Additionally, the wires all orient over to the driver's side.


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OK take a deep breath, here we go.


 Look on the bottom of the kickpanel near the hood release- you'll find a 7mm screw there - using your socket take that off and save it somewhere. The screw is easy to find on the bottom of the kickpanel, out of view but right there near the hood release.


Next,  pull the factory fuse box cover off. It's on the left side of the dash and you'll have to open the door to get access. It just pulls off.





Next we'll take a screw out of the kickpanel that was behind the factory fuse cover, seen here next to the parking brake.

Go ahead and take off that torx screw while you're there. Put both with the other screws you're removing - don't lose them.





Now we'll take one more torx screw off. It's on the side there above the actual factory fuse box. Same M15 torx.



The vent just pulls out now, no force needed. Go ahead and just leave it hanging there.

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Next we'll need access to the wiring behind the dash. Easiest is to remove the fusebox. Easier than it sounds for sure.


Looking here near the bottom, there's one single clip holding it in place. Push in the clip, pull out the bottom of the fusebox, then lower it down and let it fall out of the way.




You should easily be able to get your hand back there now - and you'll need to!



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With the fusebox out of the way, let's finish getting the kickpanel as far off as we can. I never completely removed mine; there was something on the right side I could not figure out, but I was able to gain enough access to install the fuse box and finish the wiring completely.


You'll need to separate the dash from the kickpanel. To do this, follow the seam just beneath the air vent you removed. You'll need to separate the piece above the seam from the kickpanel:




Looking behind my finger there, you'll see another 7mm screw at the top of the kickpanel, just to the right of that rectangular hole. Remove that screw and put it with the others you've removed.





Last step - with all these screws removed, and please don't forget the very first one (at the bottom of the kickpanel) it's time to pull the kickpanel outwards. There's clips on the left side near the bottom - I was able to overcome them with gentle pulling until the kickpanel popped loose.


When you're done, you should now have all sorts of access!



Note a couple things here:

1) I did not entirely remove my kickpanel. I was unable to get the right side loose. I did not want to take any further bits off the truck. I hope someone will come along in the future and maybe outline the steps to do that - I did not find it necessary to finish.

2) Unfortunately, if you're swapping out kickpanels, now's the time. Finish taking off the old one. Don't put the new one on just yet- almost there but not yet.



Edited by blamkin86
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