sircodemane
Member
- First Name
- Cody
- Joined
- Jan 6, 2025
- Threads
- 1
- Messages
- 15
- Reaction score
- 21
- Location
- Colorado, USA
- Car(s)
- 2024 MT Supra 3.0
- Thread starter
- #1
Another Audio Post. Why?
This forum has been a huge resource for me, I wanted to give back. I've done a lot to my car, including things like suspension and cutting a hole in my hood. This was by far the most tedious and frustrating project I've done so far and I want to make it as smooth as possible for others. So much time is spent bent over the bumper or squatting in the trunk trying to work on things in cramped places, so any time I can save you is worth writing this.
I also did the OEM sub improvement. I watched YouTubers react in shock and awe at how amazing the result was when they did it and that was NOT my reaction at all after I did it myself. Maybe it helped clean up the stock bass sound a tiny little bit, but it was so underwhelming for the amount of work it took (Sorry tadda! lol). If I could do it over again, I would skip that whole step and just install aftermarket sub/amp to begin with because this was worth the effort.
Credit where it is due, this will build on posts by @suprastew (Removeable $350 Subwoofer) and @tadda (Supra Amp and ASD Wiring). Those posts were great and helped get me going, but I needed a bit more information to finish and I hope to tie it all together here. Still definitely worth checking those posts out for more information and context.
Parts and tools
From here on, I will only refer to the amp side or fusebox side of the vehicle. For US vehicles, amp is driver side, fusebox is passenger side. Not sure if other markets are different, but this keeps things simple.
Start by disconnecting the positive terminal of the battery and removing the amp side trunk panels. I followed along with this video, it's a great way to see how everything comes apart. I highly recommend watching the first 4 minutes of it at least once.
I had trouble unplugging the trunk light in the side panel and found it much easier to leave it plugged in and pop the entire light out instead. Press on the tab opposite of the wires and push it down through the hole, then turn it sideways to get it back through the hole and out.
Once the trim panels are removed, you'll unplug the ASD module, dismount the wire loom, then remove the amp and unplug its connectors. Doing all of this will give you plenty of room to deal with the wiring. The video linked above also shows how to do this and shows how the speaker connector works (it was a pain for me). The one thing it does not mention is that there is a clip on the bottom of the amp bracket that you also pry up once you get the two nuts removed, similar to the white wire loom retainers.
Wiring
Now that we have access to everything we need, we can begin wiring. We need to connect the LOC to the existing sub wires, connect the 12v and ground, as well as the remote wire.
12v Power
I attached mine to the power distribution block next to the battery. You can pop off the red cover by prying it up, then route the 12v wire through the opening in the red cover.
Ground
I found two points where existing grounds are and picked one to use. One is near where the OEM amp was mounted, just over the ledge, and one was near the OEM sub box.
Remote Wire
You have two options: You can either use a fuse tap, or tap the wire on the OEM amp harness. If you choose to use a fuse tap, the fuse you'll tap into is slot F215 in the rear fuse box. This should already have a 5a mini fuse installed. Make sure to read the Pro Tip below regardless of which method you choose.
I chose to instead tap the remote wire for the OEM amp. For me, this wire was a small red wire with a black stripe that came from the rear fusebox along with other 12v power wires. However, I had 2 of these red/black wires in that bundle, so I followed it up to the amp connector that has the fiber optic connections to make sure I picked the right one:
I was able to tap my aftermarket remote wire into this wire and it worked like a charm.
PRO TIP: I wasted two afternoons on just the remote wire. I actually got it right the first time, but when I was testing everything, I saw my media screen turn off, followed by the lights on the OEM amp turning off, but the aftermarket amp was staying powered on. This led me to believe I did not correctly find a wire that would shut off with the car and feared I would drain the battery. Turns out, this is just how the car works. The screen turns off and the OEM amp seems to power down, but that F215 fused location which powers this wire stays powered for about 5 or 6 minutes after everything else powers down. Once I had this realization, I tested to make sure it powered off some time after the car "powered down" and then came back on when the car "woke up".
LOC Speaker Outputs
Luckily it's pretty easy to identify the sub outputs. The sub wires are going to be twisted pairs much larger than the other speaker wires in the loom. For me, the amp side sub was purple/yellow (+) and black/green (-), the fusebox side sub was white/black (+) and blue/black (-). Tap the LOC inputs into these wires.
If for some reason your speaker wires don't match, or if you are like me and just want to double check for yourself, you can pop the subwoofer speaker grills off and look at the connectors. They aren't secured with screws, so just pop em off and have a look. The positive wire will be on the right side (clockwise) of the connector, the negative is the left. Make sure to re-align the tabs when popping the grill back in, one side has two closely spaced tabs and the opposite side has far spaced tabs.
Wrapping Up
At this point, all that's left is to figure out where you want to mount your amp and getting it connected. This is where things become a bit more straight forward (typical amp install) and personal to what you want so I won't go into detail. Suprastew got a 700w amp that fits nicely into the cubby on the amp side (check his post for picture), but my 1500w amp wouldn't fit there so I mounted it to the amp side trunk panel. In hindsight, the 1500w amp is probably more than I needed and not being able to fit it in that cubby was kind of a bummer, but oh well.
This is how mine turned out, with an edit showing roughly how I ran wires. Red is 12v, orange is ground, blue is remote wire, yellow is speaker wire. It's also worth noting that it's much harder to remove my trunk floor now with my amp mounted where it is. I lost a good bit of wiggle room needed to finesse it out easily, so that's something to consider when picking a place for your amp.
If you have any questions, I will try to answer them in replies and update this main post to reflect those answers.
This forum has been a huge resource for me, I wanted to give back. I've done a lot to my car, including things like suspension and cutting a hole in my hood. This was by far the most tedious and frustrating project I've done so far and I want to make it as smooth as possible for others. So much time is spent bent over the bumper or squatting in the trunk trying to work on things in cramped places, so any time I can save you is worth writing this.
I also did the OEM sub improvement. I watched YouTubers react in shock and awe at how amazing the result was when they did it and that was NOT my reaction at all after I did it myself. Maybe it helped clean up the stock bass sound a tiny little bit, but it was so underwhelming for the amount of work it took (Sorry tadda! lol). If I could do it over again, I would skip that whole step and just install aftermarket sub/amp to begin with because this was worth the effort.
Credit where it is due, this will build on posts by @suprastew (Removeable $350 Subwoofer) and @tadda (Supra Amp and ASD Wiring). Those posts were great and helped get me going, but I needed a bit more information to finish and I hope to tie it all together here. Still definitely worth checking those posts out for more information and context.
Parts and tools
- Subwoofer, box, and amp of your choice (I went with Pioneer 12" Shallow + Stinger MT monoblock amp)
- Line Out Converter (I used this one from suprastew's post)
- Amp wiring kit (I used this one)
- Wire taps of your choice (I got something like these from the auto parts store)
- Optional fuse tap if you prefer it for the amp remote wire. I chose to tap mine from the amp harness instead.
- Car trim tools
- Wire cutter/stripper
- Basic hand tools (screw drivers, torx set, sockets, etc)
- It might be worth adjusting the seats as forward as possible before disconnecting the battery.
- DO NOT CLOSE THE HATCH WITH BATTERY DISCONNECTED. It is pain. If you want to partially close it, make sure to place a folded cloth over the latch.
- Once you remove a part, replace nuts, bolts, and clips back where they came from. It's a simple way to not lose things.
- Additionally, you can place painters tape over mounting points/hardware so you don't forget about it.
From here on, I will only refer to the amp side or fusebox side of the vehicle. For US vehicles, amp is driver side, fusebox is passenger side. Not sure if other markets are different, but this keeps things simple.
Start by disconnecting the positive terminal of the battery and removing the amp side trunk panels. I followed along with this video, it's a great way to see how everything comes apart. I highly recommend watching the first 4 minutes of it at least once.
I had trouble unplugging the trunk light in the side panel and found it much easier to leave it plugged in and pop the entire light out instead. Press on the tab opposite of the wires and push it down through the hole, then turn it sideways to get it back through the hole and out.
Once the trim panels are removed, you'll unplug the ASD module, dismount the wire loom, then remove the amp and unplug its connectors. Doing all of this will give you plenty of room to deal with the wiring. The video linked above also shows how to do this and shows how the speaker connector works (it was a pain for me). The one thing it does not mention is that there is a clip on the bottom of the amp bracket that you also pry up once you get the two nuts removed, similar to the white wire loom retainers.
Wiring
Now that we have access to everything we need, we can begin wiring. We need to connect the LOC to the existing sub wires, connect the 12v and ground, as well as the remote wire.
12v Power
I attached mine to the power distribution block next to the battery. You can pop off the red cover by prying it up, then route the 12v wire through the opening in the red cover.
Ground
I found two points where existing grounds are and picked one to use. One is near where the OEM amp was mounted, just over the ledge, and one was near the OEM sub box.
Remote Wire
You have two options: You can either use a fuse tap, or tap the wire on the OEM amp harness. If you choose to use a fuse tap, the fuse you'll tap into is slot F215 in the rear fuse box. This should already have a 5a mini fuse installed. Make sure to read the Pro Tip below regardless of which method you choose.
I chose to instead tap the remote wire for the OEM amp. For me, this wire was a small red wire with a black stripe that came from the rear fusebox along with other 12v power wires. However, I had 2 of these red/black wires in that bundle, so I followed it up to the amp connector that has the fiber optic connections to make sure I picked the right one:
I was able to tap my aftermarket remote wire into this wire and it worked like a charm.
PRO TIP: I wasted two afternoons on just the remote wire. I actually got it right the first time, but when I was testing everything, I saw my media screen turn off, followed by the lights on the OEM amp turning off, but the aftermarket amp was staying powered on. This led me to believe I did not correctly find a wire that would shut off with the car and feared I would drain the battery. Turns out, this is just how the car works. The screen turns off and the OEM amp seems to power down, but that F215 fused location which powers this wire stays powered for about 5 or 6 minutes after everything else powers down. Once I had this realization, I tested to make sure it powered off some time after the car "powered down" and then came back on when the car "woke up".
LOC Speaker Outputs
Luckily it's pretty easy to identify the sub outputs. The sub wires are going to be twisted pairs much larger than the other speaker wires in the loom. For me, the amp side sub was purple/yellow (+) and black/green (-), the fusebox side sub was white/black (+) and blue/black (-). Tap the LOC inputs into these wires.
If for some reason your speaker wires don't match, or if you are like me and just want to double check for yourself, you can pop the subwoofer speaker grills off and look at the connectors. They aren't secured with screws, so just pop em off and have a look. The positive wire will be on the right side (clockwise) of the connector, the negative is the left. Make sure to re-align the tabs when popping the grill back in, one side has two closely spaced tabs and the opposite side has far spaced tabs.
Wrapping Up
At this point, all that's left is to figure out where you want to mount your amp and getting it connected. This is where things become a bit more straight forward (typical amp install) and personal to what you want so I won't go into detail. Suprastew got a 700w amp that fits nicely into the cubby on the amp side (check his post for picture), but my 1500w amp wouldn't fit there so I mounted it to the amp side trunk panel. In hindsight, the 1500w amp is probably more than I needed and not being able to fit it in that cubby was kind of a bummer, but oh well.
This is how mine turned out, with an edit showing roughly how I ran wires. Red is 12v, orange is ground, blue is remote wire, yellow is speaker wire. It's also worth noting that it's much harder to remove my trunk floor now with my amp mounted where it is. I lost a good bit of wiggle room needed to finesse it out easily, so that's something to consider when picking a place for your amp.
If you have any questions, I will try to answer them in replies and update this main post to reflect those answers.
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