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2019 GMC Sierra 1500 Denali
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Discussion Starter #1 (Edited)
Welcome to my 2019 GMC Sierra Denali audio upgrade build. I will be explaining a lot of information about the gear I used, why I selected specific equipment, and how I installed it. Hopefully, this build will help spark some ideas in other's systems.

I listed the same build on GM-Trucks.com (2019 GMC Sierra 1500 Denali Audio System Build (Includes A MiniDSP Setup Guide), but that article will have both the audio system build and a step-by-step guide on setting up a MiniDSP. Because diymobileaudio has two different areas for this information and has an image limit per post, I'm only posting the truck upgrade. I have too many images in the step-by-step MiniDSP guide. Feel free to find my article on that forum page if interested in the reading. Some sections in this build may sway toward a how-to guide because the general idea was to explain some pieces in more detail to help provide ideas for others system builds.

I will list a lot of the hardware pieces that I used during this project. I may not list some of the minor stuff or tools I used, but I'll explain what I used during this build document. I created some items in this build, but I documented what I did to help give any ideas to someone wanting to attempt something similar.

This build read will be pretty lengthy, but I included headings if you would like to skip to specific sections.

Table of Contents (By Section):
  • Section 1: Audio Hardware
  • Section 2: How I choose My Audio Gear
  • Section 3: Gear Installation
    • This will be broken into a few different posts because of the 20 image limit.

Audio Hardware:
How I choose My Audio Gear:
  • Amplifier and Factory Integration:
    • JL Audio amplifiers and the NAV-TV were my final choice in this audio system build. I decided on the NAV-TV because it provides the most direct radio to DSP integration. I read several posts about people having issues with the NAV-TV unit in these trucks, but I wanted to give it a try. My NAV-TV has been strong for eight months.
  • Component Speakers:
    • First, I needed to choose to do 2-way or 3-way speakers for my front sound stage. I could do 2-way without any extreme custom mounts or 3-way with custom mounting requirements. I choose to go with the 3-way even though it would be more work because I wanted the extra mid-range sound plus nice highs. I decided to leave the mid-range in the same spot and modify the tweeters' sail panels. I knew going would make the tweeters look close to a factory.
    • Next, I needed to choose what speakers I wanted to install into my truck. I had two things in mind when purchasing speakers. First, what speakers can I fit into my truck and make modifications for fitment, but allow me to reinstall the factory speakers when I sell the truck. Second, I wanted quality and look. My 1st choice was purchasing JL Audio's C7 components, but the mid-range speakers are too large to fit into the dash without cutting away all the factory mounting. My second choice was Focal Audio. I looked at both the Flax Evo and K2 Power series. I landed on the Flax Evo because I knew I would have an exposed tweeter, and I didn't like the idea of the K2 yellow cone with my dark brown interior. The Flax EVO had a very dark brown look that would go with a brown or black interior.
      • If you are planning on putting these in your 2019+ Sierra or Silverado, know the mid-range Flax EVO components will fit into the dash but it will require cutting into the original mounting plastic area. If you do it carefully you can preserve the existing round plastic section and mounting holes if you ever planned on putting the stock gear back into your truck.
  • Subwoofer:
    • I already had a pair of JL Audio 10TW3-D4 from my previous truck, so I re-used these subwoofers and made a custom-tuned ported enclosure tuned at 32 Hz.
  • DSP:
    • MiniDSP was my primary choice from the start for two reasons. First, it has 12 channels of output, and I need nine channels because I wanted everything going through my DSP, so I could make any tweaks without touching the amplifiers. Second, this DSP can be purchased with Dirac or have Dirac added. I have Dirac on my Emotiva pre-amplifier, and it has been great, so I knew I wanted this in my truck build. Many other DSPs only has eight output channels, so it can be a limitation if you do three ways in the front, rear speakers, and a subwoofer. If I didn't choose the MiniDSP, I could have connected the rear fill speakers directly to the amplifier, but if I ever wanted to make tweaks to the speaker like the gains, I would have to pull the rear seat. Some other DSPs had cleaner graphical user interfaces (GUI) and tweaks, but using MiniDSP with REW/Dirac will give you a crazy amount of advanced tweaking if you choose. One last nice feature of the MiniDSP is the preset options on the volume control knob. You get the opportunity to choose from 4 different configuration types that you can switch live with the press of the button. The significant gain in the MiniDSP as opposed to other DSPs with no additional presets is you can tune each preset for your own needs. I have preset one tuned for windows up and the sound focused on the driver side. This tune makes the music sound as if it is right in front of my face. Preset two is tuned for windows up and center-focused to give both the passenger and driver a general sound. Preset 3 & 4 are the same as preset 1 & 2, but with the windows down tuning. These two preset make a massive difference in the sound because of glass reflection.
  • Alternator:
    • Mechman alternators were my 1st choice when looking into an alternator. The biggest issue was I couldn't find any information about any manufactures high output alternators working on the 2019+ Sierra/Silverado. After talking to Mechman they informed me they could not go above 250 Amp because the truck's stretch belt restricted using a smaller pulley used on the higher 360+ alternators. Also, they did not know if the smart charging system would cause issues with charging. They were honest and let me know I could return the alternator if it didn't work, so I was on board with giving it a go. It turned out to work, but there is a catch on these trucks. I'll explain more further into the build document.


Gear Installation:

In this section, I will show images that I took during my build process. I'll add a little explanation throughout to help answer any questions anyone may have about the procedure I took for the installation.

Subwoofer:

The first piece of this system I started with was my custom subwoofer enclosure. I spent an extended amount of time design this subwoofer box on the computer before building it. My last truck was a 2014 GMC Sierra, and I created a custom sealed box for the truck using the same speakers. It sounded good, but it didn't hit as hard as I would like. That truck had limited room under the rear seat for a ported enclosure using my selected subwoofers, so I choose to go sealed. After doing some measurements under my 2019 GMC Sierra seat, I discovered additional room under the seat compared to my 2014. I began taking measurements to see if I had enough air volume to get a ported enclosure built. After some calculations, I knew I could make this work with a good amount of tweaking. I used Visio to layout the box design to scale to make sure I could fit the box sections in specific locations and used an enclosure design software to design/tune the subwoofer box. Designing a ported enclosure for a truck with a correctly built port is critical because you will be more likely to hear port noise if the velocity is too high.

New Box Build Note: If you plan on making a custom ported box for this truck or any other truck, I recommend not porting out the box's side if the side of the box is flush with the edge of the seat. A side port will only function correctly when the door is open. Your distance between the port's opening and the adjacent solid surface should be, at minimum, the similar size to your port opening. If not, you are restricting the air from escaping the port and putting back pressure on it. That is why you will notice my port is at the front of the subwoofer box.

When I built my 2014 sealed box, I kerfed the curved sections and added additional fiberglass/mat to add strength. I decided I would create custom curved stacks for my 2019. I wanted a specific radius, so I started with cardboard to determine the curve I wanted, and I transitioned that to my MDF and used a flexible template for curves and my router.

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After I determined my curve, I created my base (1), 1/2" stack, (2) 3/4" stacks, and (1) fully top sheet. Then I used a cardboard piece to figure out the floor curve and transferred that to the bottom of the base section.

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Here is a picture of the curves and bracing. I have not glued the curves and bracing on top of the main base. I test fit all the pieces to see how everything looked.

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I created a custom jig to help be cut the angle on the top of the stack.

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All curves, bracing, and inside of the port have been installed and glued.

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I build the front using the same flexible template to get the curves the way I liked them to go over the middle hump in the floor. I made the left and right side match even though the passenger side does not have any woofers. I did this for the look and added additional room for air to escape from the bottom of the box.

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I installed the front panel and tested the box levelness since I have added more pieces of wood that weighted down different sections.

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I added additional port angles to decrease sharp edges and added some flexible rubber coating to the port. Also, I added my terminal posts to the rear of the box and installed some scrap wire for terminal connector fitment testing.

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Next, I installed the lid on the subwoofer box. I rough cut around the lid close to the box's edge and then made a custom angle jig for my router to go around the box and router off the excess.

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I added a JL Audio log to the front with ABS, and I wrapped the box with vinyl and carpet. The final step was to spray the vinyl to match the interior of the truck. I sprayed this with SEM Color Coat, but SEM did not have an exact match. It matched kind of close, but a little lighter than the factory color. I may be changing up the color in the future.

Note: I tried several different SEM vinyl sprays to get a brown that would match my interior. After spending a lot of money on spray, I had zero luck with the brown. My interior was a two-tone brown/gray color. After I couldn't find a dark brown that matched close enough, I decided to find a gray. I finally found a gray color that matched my interior. If you have a similar color interior, I suggest trying Duplicolor Vinyl and Fabric Coating in Charcoal Gray (Part# HVP111).

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I made custom aluminum brackets to bolt the box to the truck. I was able to use the factory screw pins used for the original jack hardware.

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Here are the final pictures of the subwoofer box installed in the truck.

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2019 GMC Sierra 1500 Denali
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Discussion Starter #2
Door Wiring:

Beware that these 2019+ GM trucks now have quick-release connectors for the doors outside the truck. The previous generation had the connector inside the cabin. This plug requires drilling holes through each connector to get the speaker wire installed. I wanted a 12 gauge speaker wire installed for every component, but the Stinger had too much rubber coating around the wire to go through these connectors. I decided to use some other 12 gauge speaker wire I had leftover from my home theater build that had a little less rubber coating through these connectors and then join that this wire with my Stinger 12 Gauge after the doors.

  • Note: If you want to use the same wire through the doors, you will want to go with different wire sizes.

Here is a picture of the male/female connectors before I added the holes.

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Now I added the holes to each connector. They need to line up, so after I finished the 1st connector, I connected them and drilled through both just enough to start the hole on the other connector. Then I disconnected them and finished drilling the other hole.

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I ran the wires through the holes of the inside connector.

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I am running the wires through the connector before adding the dust boot. When running these wires, make sure you don't get them twisted between the connectors.

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Tweeters:

I molded the tweeter pods into the front door sail panels. The challenging piece of this installation was the plastic flexed everywhere. It required some extra reinforcement to keep the mold from cracking during installation.

I started by figuring out a rough location that I wanted the tweeter pods that came with my Focal component set. Then I installed one screw into the pod and made a custom laser light holder. Then I aim each pod to a similar spot on the ceiling. This spot ended up being about the middle of the sunroof.

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After finding the location, I liked I added two additional screws and closed the door for a fitment test.

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Next, I started to hold the shape using body filler. Notice the backside has all the tiny holes with fiberglass resin/mat installed. Fiberglass is required and needed to strengthen the backside of this panel. Without adding this strength, the body filler will crack during the installation.

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Both pods are finally completed and sanded smooth.

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Each piece of door trim was sanded, wiped down, and coated in SEM's texture coat.

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Final installation picture of the tweeters installed.

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2019 GMC Sierra 1500 Denali
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Discussion Starter #3
Midrange:

Below are some measurements I took of the midrange speakers and mounting location. These measurements may help you determine what speaks they choose to install if you have a similar truck.

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I used these measurements to determine what speakers would fit into the dash and still keep the factory mounting points. I knew I would have to cut up parts of the plastic, but my only concern was maintaining the factory mounting holes. I switch to a new Sierra every new generation, so I wanted to transfer this system into my future truck. Below is are two comparison pictures between the factory speaker and
3" Focal Flax Evo.

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You can notice I took a significate amount of plastic away to fit the Focal midrange speaker, but the factory mounting holes remain. I used some sound-dampening material around the edges and on the factory mounting holes to prevent any rattling.

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Final picture with the Focal midrange installed.

Note: This 3" Focal midrange gave just enough room to install the covers. Any larger speaker would have required me to remove the factory holes so that the midrange could sit deeper into the hole.

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Woofers/Rear Coax/Sound Dampening:

I wanted to have a sold transition between the speaker and the door for my door woofers and rear coaxial speakers, so I choose to build custom mounting adapters for these speakers. The most accessible source for me to get some adapter building material was using 1" PVC Trim Board from Menards. I purchased the PVC Trim Boards as well as some wood inserts. I used inserts because this PVC Trim Board is not strong enough to secure your woofers. I did not take many pictures during this process, but I'll explain what I did below.

Note: This material cuts like MDF, so be aware of the mess.

I took an aftermarket cheaper plastic adapter kit to build these mounts and used double-sided tape to run my router around the template to form the outer base. I created the outer piece to match the style of the factory speaker. Then I used PVC glue to bond the two pieces together. Each piece bonded @ 1" equaled 1.5" (actual). I used clamps to hold them for 24 hours. I only have glue between the base and outer, but I put two sets per clamp set.

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Then I used clamps and drilled holes through the base into my door. I did a screw/nut installation for these custom adapters because I didn't have an insert tool on hand, and I didn't see the need to purchase one just for easier removal of these adapters.

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Final adapters with inserts installed.

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Next, I added Stinger RoadKill foam to each adapter. Also, I had some Parts Express gasket tape for an extra seal against the door. Adding the gaskets is worth the extra step because it funnels the sound out the door. Without having the gaskets, you may lose some of the sounds inside the door between the metal part of the door and the outer door panel.

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Here is the adapters installed and the added sound dampening material to help seal the doors for better sound.

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Woofer installed into the door speaker.

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Discussion Starter #4
Rear Seat Amplifier Board:

The amplifier board on the rear seat took me some time to figure out the layout I wanted to do.

I needed to set up the amplifier board for two different configurations. I'll explain both configurations.

  • 1st Configuration: I wanted to test using a single amplifier and with the Focal crossovers. This setup allowed me to listen to the set up so that I could compare it with the DSP. I did not document this build setup, but I mention the DSP section's differences further in this document.

  • 2nd Configuration (Final): I had to plan the location I wanted my additional components (Additional Amplifier and DSP) to remove the crossover.

Before I started, I took a picture of all the factory components behind the seat to draw on this image for component placement.

Notice the cab vents on each side of the truck. You want to avoid blocking these as much as you can to prevent any issues with cabinet pressure. Blocking them can cause problems with your doors closing smoothly and your heat/ac not working correctly.

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I removed all the components from the rear wall and cut strips of 1/2" MDF, and glued them to the back wall with contact cement. A few of the pieces I kerfed to allow them to bend with the flow of the metal.

  • Note: I had to cut the mount points for the factory amplifier and the AC/DC converter. When I sell the truck, I will leave the amplifier boards I created to mount these components back onto the truck.

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I added sound deadening material to the back wall and over the pieces of MDF.

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I created two different amplifier mounting boards to install all of my components. I pre-drilled/countersunk holes in the MDF. Then I drilled through each hole into the MDF mounting strips. After, I removed the MDF amplifier boards and added threaded inserts into the MDF. I let the glue on the inserts set up for 24 hours, and I came back and mounted the amplifier boards to test fitment.

  • Note1: After test fitting the rear driver side plastic trim covering the seatbelt section, I noticed the amplifier board would not sit behind the trim. I trimmed that section down after determined the amplifier placement.

  • Note2: I added some additional threaded inserts to the mounting panels after making a few tweaks.

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Below are all my components installed. I created custom-length RCA cables to look clean and lessened the need to bundle a bunch of wires.

  • Note1: I moved the AC/DC converter near the underside of the rear driver side vent. When I laid out the amplifier boards with all the components, I had no room for this converter to go besides this location. No water gets through these flaps, but dust can build over time. Depending on your driving conditions, you may want to pull the rear seat every so often to blow out this converter and your amplifiers as well.

  • Note2: I have RCA and Toslink ran between my NAV-TV and Mini-DSP. It is worth having both connected now in case of a software bug issue with one of the connections.

  • Note3: The MiniDSP only allows updates through the SD card. I tried a few SD extensions to eliminate removing the back seat, but the extension cables did not work. You will have to remove the rear seat if you ever need to update the MiniDSP.

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I used double-sided sticky tape to install the bass/preset control next to the driver seat.

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I had to cut some of the rear seat foam for fitment. I removed as little seat foam as possible to prevent from hearing the rear cab vents. The foam is sound deadening for outside noise. If you remove all the foam or too much, you will listen to more outside noise. I also installed an amplifier behind the rear seat on the driver side and had to modify the seat storage compartment. I had to cut away some plastic and shrink the inside storage compartment down a little. I did not want to remove it altogether or make it unusable. The image below shows that I cut a section out of the side and force it down with a bit of overlap. I screwed, and plastic bonded the pieces together. I had to modify several sections of this storage compartment. I only took one picture during this process.

I did not include the rear seat installation images, but I wanted to give a heads up on possible complications if anyone chooses to do a similar build. You may struggle to get the rear seat to latch into the top 3 sections. Verify you do not have any foam causing restrictions. All my foam was good, but my rear latches did not want to hook. The trick for me was getting the top 3 latches connected first and adding the bottom bolts afterward. All the audio components are up against the foam, which can cause issues with getting the latching to occur. Instead of removing all the foam, this process allowed me to get the rear seat installed and allowed the components to press into the foam for an excellent snug fit.

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Discussion Starter #5
Alternator:

My factory 2019 GMC Sierra Denali 1500 6.2L comes equipped with a 170 amp alternator. My past 2014 GMC Sierra had less alternator amperage. I could notice the power drop with only subwoofers added, so for my new system build, I was going even bigger, and I did not want any protentional power loss. I wanted higher wattage at both idle and normal driving. Also, since I invested so much time and money into my audio system, it's worth the additional cost of adding some extra amperage. My new audio system's total max watts is 2,200. Some people may have a much higher watt audio system, and the 250 may not be big enough, but adding the 250 will still give you an additional 80 amps, which is more than the factory. GM offered a 220 amp alternator upgrade kit for these trucks, but it would exceed the factory fuse rating, so I would have needed to upgrade the OEM wiring harness. I choose not to investigate because I wanted more amperage than 220 amps. At this point, I knew I needed to call Mechman to discuss my alternator upgrade needs.

After talking to Mechman they informed me my truck had a stretch belt, which limited my alternator amperage selection to 250 amps. Two hundred fifty amps are the highest amperage these trucks can go per Mechman (As of 9/11/2020). The higher amperage alternators require a smaller pulley, so the alternator can spin faster to create more amperage. There is no extra play for a smaller pulley with a stretch belt because you do not have a belt tensioner. The primary issue I ran into was Mechman did not know if the 250 amp alternator would function in my 2019 GMC Sierra 1500 Denali because of the smart charging system. At this time, they had no confirmation that any of the 2019+ GM Silverado/Sierra 1500s would work. Mechman gave me the option to give the installation a try, and if it didn't work, they would allow me to return the alternator without any issue. If this did not work, I would be out all the wiring upgrade, air intake costs, and time. I choose to take the gamble. The good news is I can confirm the alternator does work in the 2019+ GM Silverado/Sierra 1500s, but I do have a little bad news.

For some reason, GM decided on these trucks they would make an air intake system that stretches clear across the front side of the motor in a substantial plastic box, which is probably for some extra emissions reduction. The main issue is they decided to add the support bracket for this large air intake box to the factory alternator. Mechman's alternators are not purpose-built for this truck generation, and they sent me one for the 2014-2018 model year, thinking it would match up just fine. The alternator mounting bolts and pulley size are correct, but it is missing this mounting bracket. I eliminated this factory air intake issue by choosing to install an Airaid Junior Air Intake System. This system is the least expensive out of all air intake upgrades, and it removes the factory large plastic intake box but leaves the factory filter enclosure. I wasn't concerned about the air filter enclosure. I'm not going to go into my reasons for that. You do get an excellent cleanable air filter that fits in the factory enclosure.

The factory alternator wiring does not have the correct wire gauge and fuse to support a 250 amp alternator from Mechman. I had to upgrade all the wiring between the alternator and the battery. This upgrade includes positive and negative wires. I used Stinger wiring for my audio upgrade, so I decided to use the same wire and fuse block for this alternator upgrade. This wire is Stinger 1/0 gauge wire and Stingers inline ANL fuse holder. I added a fuse holder to protect the wire in the event of a crash, so make sure you add a fuse holder. Using this wire makes sure you use a 300 amp fuse on this alternator because the alternator can exceed 250 amps, which will blow a 250 amp fuse. Also, I would recommend having a spare 300 amp fuse and installation tool in your glove box if something ever happens and you needed to change out the fuse. These are not fuses you can get at your local hardware stores.


WARNING: If you are using a different 1/0 gauge wire, make sure the wire is rated to handle at least 300 amps.

WARNING: Do not just upgrade the positive wire and not the negative. You can cause significant damage or even a fire.


I'm sure at this point you are ready to read about the installation and see some pictures.

To start, I want to show the factory alternator with the air intake box above, so you can see the mounting bracket that comes off the factory air intake.

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Here is a side-by-side comparison of the two alternators. The left is the Mechman alternator, and the right is the factory alternator. You can notice the factory air box bracket more clearly in this picture.

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My first step was removing the alternator is removing the stretch belt. I tried to look up some easy removal tools for the stretch belt, but I couldn't find any information. I tried buying Lisle Stretch Belt Remover/Installation tool, and it did not work. My recommendation is to purchase or have some plastic door/trim panel pry tools to remove the belt. The picture box (Square 1) works to remove the belt. I used the factory alternator bolt to remove the belt. I removed the belt from above the engine. The picture box (Square 2) works to install the belt. Mechman's alternator pulley bolt will not install the belt because the bolt spins freely and will not move the belt. I used the pulley bolt where the picture box (Square 2) shows. A large breaker bar helped here. I had to remove the bottom front lower engine splash shield to reach the bolt and slide on the belt. I got the belt most of the way from the bottom, went above the engine, and finished spinning the belt using the same bolt/breaker bar while pushing the belt onto the upper right pulley. If you try doing the entire install from the bottom, the belt will not seat correctly. Once you pull the belt, you will need to remove the radiator cooling fan that sits in front of the alternator to remove the bottom alternator bolt. The fan is installed with three Torx screws.

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I created a custom fuse block holder out of aluminum to hold both my fuse blocks. I used 2" wide aluminum from Menards, which does allow you to bend without heat. If you choose to do this exact mounting location, it works excellent, and you can use the mounting pin. I had to expand/cut the plastic top and base where the 1/0 gauge wires run through.

I added a 90-degree bend on the engine side of the aluminum fuse block mounting bracket to level out the bracket and give room for the 1/0 gauge wires to run underneath. The main thing to take into consideration is the negative battery terminal. I had to mount these fuse blocks to allow the ability to disconnect the negative battery lead during maintenance still. I wanted to have these fuse blocks run in parallel, but using 4" wide aluminum would cover up the ground and require the fuse blocks to be removed to connect the ground wire.

I ran a 1/0 gauge wire back to my audio system's distribution block and ran another 1/0 gauge wire over to my alternator.

  • Note1: The factory power wire on the alternator needs to be disconnected and not used.

  • Note2: The alternator will come with a 1/0 gauge terminal you can use for the wire, so you do not need any terminal for this wire back to the fuse block. You will need a standard gauge battery terminal connector to connect the fuse holder to the factory mounting location.

  • Note3: I used some heat-resistant tape on both my ground and positive wires near the engine. I recommend adding this to protect the rubber shielding on your wires from potentially melting.

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I had to run a new 1/0 gauge negative wire from the alternator and use one of the alternator's mounting bolts to hold the 1/0 ring terminal. The ring terminal that came with the 1/0 gauge wiring kit for my amplifier did not have a large enough hole for the alternator mounting bolt. I use a step bit to increase the hole size to fit snug around the bolt. After I got the negative wire ran from the alternator bolt, I needed to remove the factory ground wire and connect the new 1/0 gauge wire directly to the mounting point the factory wire installed. I had a smaller 1/0 gauge ring terminal that worked perfectly.

  • Note: Do not connect the factory ground and alternator ground. Connecting this wire will throw off the smart charging system.

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This picture shows me adding some heat shrink to the factory's positive and negative wires. I choose to leave the factory positive and negative wires under the hood. My goal is to remove this system before I trade the truck in for a newer model year, so if this alternator works with that model year, I will be putting the factory alternator back into the truck.

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Here is a picture of me securing the factory power wire. I secured the ground wire near the firewall, and there isn't an easy way to take a picture.

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Since I choose to add the same fuse blocks for my audio and amplifier, I wanted to label both fuse blocks. Below are a few pictures of each fuse labeled fuse block. I added the label to the cover and the fuse mounting point. I did this just in case the covers got installed incorrectly.

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Here are the final pictures of the installation of the Mechman alternator and the Airaid Junior.

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You reached the end of my system build. Hopefully, this build helped you come up with some new ideas for your next audio project.
 

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Excellent work and great documentation!
 
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There are a few of us here that are getting ready to install systems in GM crew cabs. It would appear to me that you have set the bar for the rest of us. The planning, layout, fabrication and execution are all top notch, excellent work.
How does it sound?
 

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2019 GMC Sierra 1500 Denali
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Discussion Starter #10
There are a few of us here that are getting ready to install systems in GM crew cabs. It would appear to me that you have set the bar for the rest of us. The planning, layout, fabrication and execution are all top notch, excellent work.
How does it sound?
The clarity in the system is impressive. At times I will find songs I haven't heard for years, and once it comes on over the system, I smile. I had a crazy amount of hours in this build, but it was worth it in the end. The extra effort in adding the tweeters made a huge difference as well.

Also, a significant gain in the MiniDSP is the four presets which help with that clarity. I explained these more in my MiniDSP step-by-step section in the guide on GM-Trucks, so it's missing from this build explanation. I'll make an update. The significant gain is you can tune each preset for your own needs. I have preset one tuned for windows up and the sound focused on the driver side. This tune makes the music sound as if it is right in front of my face. Preset two is tuned for windows up and center-focused to give both the passenger and driver a general sound. Preset 3 & 4 are the same as preset 1 & 2, but with the windows down tuning. These two preset make a massive difference in the sound because of glass reflection. If you like to roll down the road with the windows down and jam some music, you can change the preset on the fly and hear how much better you can listen to the music.
 

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This is INCREDIBLE!!!! In 4,000 years I may have this level of skill.
 

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Great write up I will be starting my upgrade in my 2020 Sierra soon hopefully, I do have a few quick questions, mine is 6.2/max tow pkg so I have the larger alternator already 220 amp I believe, do you know of a way to bypass the "smart charging" on the alternator my voltage is all over the place depending on how much it thinks it needs to charge just curious if this will be an issue or if the variable output will adjust to the additional load? second question how much depth is available behind the rear seat? I have 3 small amps and the helix DSP to mount back there just curious if you think they can be placed strategically to avoid the storage pockets? and Last do you know of any other integration options other than Nav tv? mine is non bose so that is not an option for me, currently planning on using a basic speaker level harness from Jon over on the GMC truck forum.
 

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Great write up I will be starting my upgrade in my 2020 Sierra soon hopefully, I do have a few quick questions, mine is 6.2/max tow pkg so I have the larger alternator already 220 amp I believe, do you know of a way to bypass the "smart charging" on the alternator my voltage is all over the place depending on how much it thinks it needs to charge just curious if this will be an issue or if the variable output will adjust to the additional load? second question how much depth is available behind the rear seat? I have 3 small amps and the helix DSP to mount back there just curious if you think they can be placed strategically to avoid the storage pockets? and Last do you know of any other integration options other than Nav tv? mine is non bose so that is not an option for me, currently planning on using a basic speaker level harness from Jon over on the GMC truck forum.
You will not be able to bypass the "smart charging system". The variable voltage is unavoidable, but your audio gear "should" be able to handle the voltage fluctuation.

The seat's middle is your deepest area to add gear without modifying any seat compartment's plastic. My wallboard is 1/2" thick, and the JL HD750/1 amplifier is 2" deep. That is pushing the max behind the seat. If your gear is any deeper than 2" - 2 1/4" and you choose to use a 1/2" thick wallboard, you may struggle to get the backseat to bolt at the bottom. If you can fit all your amplifiers in this section, you may have a higher chance of not modifying the seat compartment. I listed the model of gear I used, so you could look up those component's dimensions to get an idea of how much space I'm using in that section. The JL Audio XD amplifier on the side is 2 inches deep, but this required modification to the seat compartment's plastic. The modified storage compartment is still usable and looks clean when open, but the space is a little smaller inside. If your Helix DPS is not as deep, you could try installing the DSP in that section, and you may not have to modify the plastic, but you will have to test fit to know. I would recommend creating your wallboards first and make some cardboard cutouts that match your gear dimensions to figure placement.

I'm not aware of the recommended way for the non-bose. Still, as long as the non-bose radio isn't doing any time correction for the individual speakers, you should be fine using the high-level inputs directly into your DSP.
 
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