2021+ Trailblazer Speaker/Amp Installation Instructions
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Crutchfield is a great source for this type of information. I used them in the past, and they were more than willing to answer my questions.
I love these type of postings in forums. Can help people decide if they can do it themselves, or have it done by the pro's
I love these type of postings in forums. Can help people decide if they can do it themselves, or have it done by the pro's
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24 Posts
What model do you have
LT with the 8" touch screen. 6 speakers.
For anyone looking to install an amp, check the RPO parts list sticker in the rear hatch.
RPO / Tuner or factory amp location
IOR Behind glove box
IOS / IOT Rear passenger cargo panel
I have IOR so I took some pictures of where my factory tuner is. Only AWD models have a factory amp with non-bose audio, so my FWD only has the tuner module.
IOR Tuner Module
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There is a factory supplied power wire grommet with a nipple on it. Cut off the nipple to reveal the hole, then push an awl or screwdriver through the firewall a few times to open up the grommet hole. Then you can easily fish your power wire through.
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From the battery side, you can barely squeeze your arm through to grab the wire and pull it up.
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There's already a power distribution plate installed from the factory, so I chose the nut that had no wires attached, then routed it along with the other wires.
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For your ground wire, there's already a nice ground point right next to the rear hatch fuse box panel. You can barely fit a wrench on it and turn it off by hand, then slip over the eye ring. The paint is already sanded off and everything.
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I also liked how the there is already wire cutouts in the carpet for running wires through.
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RPO / Tuner or factory amp location
IOR Behind glove box
IOS / IOT Rear passenger cargo panel
I have IOR so I took some pictures of where my factory tuner is. Only AWD models have a factory amp with non-bose audio, so my FWD only has the tuner module.
IOR Tuner Module
There is a factory supplied power wire grommet with a nipple on it. Cut off the nipple to reveal the hole, then push an awl or screwdriver through the firewall a few times to open up the grommet hole. Then you can easily fish your power wire through.
From the battery side, you can barely squeeze your arm through to grab the wire and pull it up.
There's already a power distribution plate installed from the factory, so I chose the nut that had no wires attached, then routed it along with the other wires.
For your ground wire, there's already a nice ground point right next to the rear hatch fuse box panel. You can barely fit a wrench on it and turn it off by hand, then slip over the eye ring. The paint is already sanded off and everything.
I also liked how the there is already wire cutouts in the carpet for running wires through.
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4 Posts
Nice and detailed! I'm trying to look into installing one myself and didn't think the battery had so much going on. Any reason you choose the upper bolt/nut to tap into for power vs the one closer to the actual terminal? I guess I pictured most car batteries looking similar and had not taken off the caps from this car yet to see all of that going on.
Now I just need to figure out where the heck my wires to splice into live, you're right the guide is nice to have but there seems to be many variations. Trying to find the best place to tap my grey and whites into. I'm curious since mine doesn't have the built in sub if I can simply use those if they are wires that go to nothing or if I need to tap into the front speakers (or back ones? Not sure which is better, I'm a noob at this stuff but with pictures feel confident!)
Generally you don't want to attach too many wires to the same point as it can create multi-path interference. I used the nut on top because nothing was attached to that one.
The best place to start is go ahead and remove some panels and see where your tuner and/or amplifier is located. Then check the colors of the harness connectors to know which T-Harness to buy from lljcustoms.
That way you won't have to cut any wires, just plug n play.
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5 Posts
Hey @JoeyTB, thanks for all the awesome pics. You are making this a whole lot easier for me. One question though, I've identified my RPO sticker says IOR, but I have no tuner behind my glove box. It's empty. I was hoping to find something like yours. But I have the basest of base trim, I know for sure there is no amp in the other two rear spots they would be. Now wondering if I have to get a harness to go directly from the head unit. Hoping LLJ Customs has one. Any insight would be greatly appreciated!
Unless something changed since I got mine, all front wheel drive models that do not have Bose will have a tuner located behind the glove box.
All wheel drive models, regardless of trim or options, will have an amp located in the rear passenger hatch.
Can you look under the center console?
If you look by the gas pedal, there will be a few push clips that hold it on. Release them then you can remove the cover. Look for a tuner there.
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