Installing old system in new truck?

My previous system i had a cheapo 15$ rca adapater that you connect positive and negative of a speaker to create an rca jack to install a amplifier. The next audio shop said i needed a 150$ one or all id hear is distortion. I told them well im going to try this box out first before you rip me off. Sure enough it worked!

So my question is will it work on my sr5 truck? i can take a picture of it later when i get home so you can see exactly what im talking about. I just want to know before i spend my time taking my truck apart and splicing wires. Just to find out my efforts are worthless.

Also where is my ignition wire? Can i just tap into my hardwired radar detector?

 

Anyone? Do I need a picture?

 

Okay after more search button ive found my answer... I have a pac line output(like this)
http://www.sonicelectronix.com/item_18107_PAC-SNI-45T.html

Where do i install it at? after the amp or after the headunit?

 

and can someone send me a wiring schematic?

 

I had a Scosche Line Level Converter (Wal-Mart $20) in my 2008 VW for a while with the stock head unit and two 10" subwoofers and 900w amp. Just ran regular speaker wires that were tapped into the FL FR, RL RR speaker wires from the factory head unit, to the line level converter...then the RCA's from there to the amp.

 

I'm going to start a thread on how to do install for trucks with and w/o jbl system.
If you have a jbl system there's a way to install an aftermarket amp without a line out converter. That allows you to use you bass control on the headunit for your aftermarket sub.

Without a jbl system you need a line out converter and it has to be installed after headunit.

If anyone has a wiring schematic for after headunit and at the jbl amp I'd like to have it so I can make a better DIY thread