help with stock headunit with external amp install

[Run 4runner run]

I am trying to figure out what exactly I will need in order to retain my stock head unit but install an external amp to drive my sub. I've seen everything from a new wiring harness to a 2-channel line out adapter but I am having a hard time determining how all this information connections (literally haha). I've done a couple sub + amp installs, but I have never done one with the stock headunit. Has anyone done this or could chime in? thanks!

 

[rjaudi]

You need a line output converter. Converts speaker wire inputs into the rca connections for the amplifier.

 

[Run 4runner run]

You need a line output converter. Converts speaker wire inputs into the rca connections for the amplifier.

Would I just tap into the harness in the back of the radio? Or is there some place to connect it?

 

[Jefe23]

There are two ways you can add a sub amp and sub to a factory head unit. You can either use a line output converter (tap into front or rear speaker outputs from the head unit making sure polarity is correct then running RCA's to your amp) or you can run high-level outputs from the head unit (basically speaker wire) if your amp can accommodate that type of input.

The only caveat to this is that most of our rigs have a factory amplifier behind the stock head unit. I've wired sub amps both pre and post factory amp output and they will work fine. (This particular stock amp is not crossed over if you pick up the rear speakers and will work for a sub application)

Hopefully this isn't too confusing and let me know if you have any other questions.

 

[Run 4runner run]

There are two ways you can add a sub amp and sub to a factory head unit. You can either use a line output converter (tap into front or rear speaker outputs from the head unit making sure polarity is correct then running RCA's to your amp) or you can run high-level outputs from the head unit (basically speaker wire) if your amp can accommodate that type of input.

The only caveat to this is that most of our rigs have a factory amplifier behind the stock head unit. I've wired sub amps both pre and post factory amp output and they will work fine. (This particular stock amp is not crossed over if you pick up the rear speakers and will work for a sub application)

Hopefully this isn't too confusing and let me know if you have any other questions.

That makes perfect sense now. I'll have to check my amp to determine which way will work; thank you so much for the help, I probably would have broken something without it haha.