wiring an amp and subs using factory head unit

im fairly new to this i have done a little bit f research but im not clearly understanding, all the setups ive ever done ive ran a power wire straight to the battery, rca cables to the head unit and find a ground somewhere close and hook up that way, but what ive heard is i can hook up a amp and subs to the factory radio and thats what im trying to do now, from what I understand, there's a harness you have to purchase that plugs into the back of the radio that allows you to run rca cables to the new amp but they told me i have to splice into the door speaker wires for something... Im not understanding how or why i would have to do that and youtube isnt helping they are doing a bunch of extra stuff i dont understand either lol i want to just run speakers off the factory head unit can anyone shed some info on this if you have done it.

 

The reason the LOC has to be hooked into the door speakers is because that's how your getting the music from the haunt l head unit to the amp. You don't want to go from speaker wires straight to rca to amp because it's wrong range. The loc takes high range and turns to low range which is what subwoofer wants. If you're using to add a amp and sub then find the 2 back for speaker or front speaker wires hook them up with speaker wire run it to loc hook loc power remote and ground to amp then hook the rca coming out the loc into the rca on amp

 

An LOC converts high voltage to low voltage, not frequency range, and most amps nowadays accept high level/high voltage inputs so an LOC isn't necessary, unless you're getting a "smart" LOC with bass restoration like the Audiocontrol line of LOC's. Also make sure if you're grabbing power and ground directly from your amps terminals that you put a small inline fuse between the amp and LOC or you risk burning it up.

Getting a harness that plugs in at the factory amp or behind the head unit simply gives you an extra bundle of wiring that you can splice into rather than cutting any factory wires. Identify one of the door speakers, cut the new harness, and add pig tails to make your own T-harness to use as input for adding an amp. The reason you'll see a lot of folks with Tundras use a LOC is for the bass restoration in a smart LOC since the factory Tundra head unit EQ's the signal so it's not flat and/or full range.

 

Sadly my amp didn't have high low so I had to use loc... but I just got new head unit in mail I'm installing as we type this lol.. and snert explained way better then I did... I was just answering because the thread was so old lol

 

Is your current head unit a JBL? - your profile state 2014 Tundra Limited. Thought all Limited came with JBL.

@Snert - doesnt JBL hook up differently than non-JBL ???

 

Good catch! I didn't know notice his profile says limited so you're probably right he has JBL, and you're also right JBL and non-JBL do wire up differently. Auto Harness House has a little blurb that mentions in JBL the head unit and factory amp are tied together in that the amp does volume control and equalization so you can't really replace one without replacing both, but as far as wiring goes I know Auto Harness House also has a little blurb to email them if you have JBL and I'd imagine you can still get a harness that plugs in at the factory amp location with bare wire ends to use for input/output using factory wiring just like in the non-JBL, could also run RCA's in that scenario but the factory wirings just as good and would be less work to use it.

 

do they make a beatsonic powered amp for your year ? it has subwoofer outs on it you could use to feed into your sub amp ?