Amp install questions

My box is on the way from Tech12Volts with two JL 10TW1s. I will be running a Memphis PR1x1000 for the subs and a Memphis MC4.75 for mids/highs (the Hertz Uno/JL package, also from Tech12Volts). The amp (and wiring) is the only thing left from the factory JBL system. I need to get everything else ordered that will be needed for the install.

I have a DC and will either install the amps under the front seats or on the back wall. About how many ft of power cable is needed for either of these locations? How many ft of RCAs for either location? Any suggestions on affordable kits that aren't garbage?

I am planning to run the power cable through the grommet on the driver's side, what is the largest cable that will fit? My buddy that will be helping me, used to own a car audio shop, and told me I should either run 1/0 to a distribution block and then 4ga and 8ga to the amps, or run a 4ga and an 8ga from the battery to the amps.

 

Did you not get the amp from James? I believe James provides all the wiring with his kits. You should check with him before you buy anything. When I purchased through I received an amp install kit with all the wiring and terminals necessary for install.

I think trying to run larger than 4ga through the grommet would be difficult to keep clean.

 

I was able to get a 4ga through the grommet, it was tight, so I agree with AZBoatHauler, anything bigger might be a challenge. I cut the nipple off of the grommet and pushed the wire from inside the cab to the engine bay.
I have a CrewMax and 18 ft was more than enough to run under the passenger seat.

 

No, I did not order the amps from James. I only ordered the door and dash speakers last month and the subs and box last week, but I guess he could always surprise me . I just don't have a lot of free time available, and I'm off this weekend, so I wanted to try and have everything needed in case I can work on it.

I thought that I had read that 4ga was about as big as would fit through the grommet, but I couldn't remember. I'm not sure what the best option is then. I could run the 4ga and try to find a place to squeeze the 8ga. I know the worst part about running the wires for my tailgate cam was getting them through the firewall. Is running the power cable along the frame a bad idea? Not knowing where the amps will be located is not ideal, but I don't know if the 4ch will fit under the passenger seat. The back wall would be ideal, easier to get to for adjustments, don't have to worry about spills, mud, or little hands/feet getting to them. The problems are that I would need more power cable than I think most kits come with (20ft is the most I've seen) and I would need to run additional speaker wire to the factory wires under the passenger seat (not too big of a deal).

 

Call James and but the Toyota factory harnesses from him so you don’t hav to cut any wires and maybe he will hook you up with the factory wiring diagram so you know which wires correspond to each speaker,

 

I personally would not run wire under the truck (on the frame), if something were to happen, like some sort of freak accident, you now have a very large positive battery wire grounding out on your frame rail. To be honest, "1/0 to a distribution block and then 4ga and 8ga to the amps" is a pretty good plan. You could always drill another hole in the firewall and add a grommet, for that specific wire size that you want to use. I was considering that myself, and there appears to be plenty of space to do that.

 

I actually bought the adapter I need from Autoharnesshouse.com. Since I have a JBL truck, I had to email to ask about the right harness, the one listed on their site is for non-JBL. I believe they are the ones that make the harnesses for James. The only reason I didn't order the harness from James is his has more than I need. Since his is to bypass the factory amp without removing it, it has more connections. The harness I ordered only plugs into the factory wiring harness of the speakers and has bare wires to connect to the new amp. If I don't put the 4ch amp under the passenger seat I'll just have to run speaker wire from the harness to the new amps. They also include the pin out/wiring diagram with the harness.

 

I didn't think it was a good idea, but I knew I would be able to get larger wire into the cab easier that way.

 

Oh, and just got my tracking numbers, I should have the subs and box on Thursday!

 

Would I need a capacitor?

 

A capacitor does not solve amperage problems. There are many steps you can take before that. A capacitor might solve your power problem as it pertains to the amps for a short time but you will still be running a deficit of power. Capacitor should always come after the Big 3 wire upgrade as well as an alternator that is meant to provide the proper power output you need for your given accessories. With that being said if the stereo is your only addition to the truck that needs powering most likely not.

 

https://www.mtx.com/library-car-audio-capacitors
Read the paragraph under VOLTAGE STABILITY

 

A capacitor is basically a battery that keeps the power to your stereo from hitting peaks and valleys, but if you have a power deficit the only way to solve it is running larger gauge wire and a larger alternator. Without that a capacitor is basically a band aid to a problem you will have to address in the future.

 

Also if your battery isn’t big enough upgrading it can help you mitigate this.

 

I removed the stock JBL amp and James provided all the harnesses need for the install. Why would someone leave the factory amp in place if they were going to bypass it anyway?

 

Ok, all I really know about capacitors, is that they store energy. For car audio, I knew that if you ran high wattage amps, you're lights would dim when the bass hit hard. I never had to worry about it before, lol, but these amps are significantly bigger than the one I had when I was younger. I actually had an article on the Big 3 Upgrade pulled up yesterday but I didn't get a chance to read it. Just glanced at an article to see what they are, and seems relatively straight forward, but do I leave the factory wires in place and add the larger ones? The stereo is my only powered addition right now. The only other powered mods planned right now are in the retrofit headlights I'm doing (HIDs, demon eyes, halos).

 

You should be fine. So your lights would dim because the instant draw on the battery was too much for the battery to provide instantaneously. It may have been the system was pulling more than your electrical system could provide therefore over time you will wind up with a dead battery or burnt out alternator. Who knows. You need to find out how many amperes your using with a simple conversion from watts and see if that exceeds the amps your alternator is providing. If it’s within range AND you have dimming lights a capacitor will be your answer. If it’s not in your electrical systems range then a capacitor is a band aid for a bigger problem and you will have issues with your electrical system(battery burns out fast, frequent dead batteries, overly burdened alternator and wiring).

 

Alternator AMPS- minus power needed for running the truck-minus AMPS required for your stereo. If this is close to or below zero you should do the big 3 and upgrade alternator. This calculation will also give you an idea of what other mods are within your power range IE lightbars, winch, compressor, etc...

 

It's my understanding that if you are keeping the factory head unit, you have to leave the amp in place and buy a DSP. Apparently the amp processes the signals and controls the volume. I replaced my HU last year, so the factory amp will won't be needed. The harness James sent me a link to said this: With the Jbl system you have to leave the factory amplifier in place due to the volume control being built into the factory jbl amplifier.

 

Nope...you buy the DSP to replace the "processing" done by the stock amp. The setup is stock HU--->DSP--->Aftermarket amp. This is my setup and with the exception of Waze audio prompts everything works perfectly.

 

Edited my comment above with a portion of the description from the website of the harness James recommended. The amp processes the signals, but it, or a DSP, is needed because the factory HU doesn't send out full signals to the speakers. Here is another excerpt from the description: No speaker in the system has full range signal so a processor is a must when adding amps to the factory head unit.

Obviously I'm not an expert, I can only go by what I've read. Also, the harness is for '14-'17, it looks like your truck is a '20, so maybe things changed? I have no idea. All I know is it none of it pertains to me, lol.

 

I'm no expert either but I've never seen anyone keep the factory amp when adding an aftermarket amp. Many/most just add the Rockford Fosgate DSR-1 since it's relatively cheap and it allows additional features not available with the stock amp. The TO3 harness handles all the connections and it's all plug-n-play - couldn't be easier.

 

For my setup (which I just completed a week ago), I ran a 100% oxygen free copper 1/0 gauge cable from the battery, through a huge fuse block, through the big firewall rubber "grommet" (which I had to do a little trimming with an X-acto knife to get that thick diameter cable through), down the driver-side floor channel, back to the voids under the back seats (where I have installed the amps) through a Stinger distribution block, splitting to two 100% oxygen free copper 4 gauge wires and out to both amps. I STRESS the use of 100% copper free wires as my last build (Toyota 4Runner), I used a lot of copper-clad aluminum wiring to save some money, and had ALL sorts of problems with it! There is a seller on Amazon that sells welding supplies and lists several 100% oxygen free copper wire products at VERY reasonable prices. For the positive 1/0 cable that I ran from battery terminal, to the back seats, I purchased 15 feet and that was JUST ENOUGH to complete the run. For the negative 1/0 cable, I purchased 5 feet but ended up only using about 2 feet. Hope that helps and good luck!