I have a set of JL 12's along with an mtx amp lined up but before i buy i want to know if anyone has wired into the stock radio yet?
is the process hard?

 

i tapped my rear speakers for the signal to my RE subs

 

when you tapped your rear speakers for that, did the rear speakers work then? or do they work but not as loud. Never messed with leaving a factory radio in and amping it this will be my first.

I normally start from scratch new head unit down and use rca's and no internal radio power this time I may just use internal power for main speakers and just amp the sub for now. then again I may just get a 5 channel amp and do it right (well with using the stock radio )

 

Beware the challenges. Recently went through this experience and not having done it recently on a newer vehicle it didn't go as planned. My stock setup was the Alpine gazillion speaker system...most of which are useless.

No speaker wires come out of the factory head unit much less RCA's. You would need to grab the wires after they already come out of the factory amp and go from there. Tried a JL summing device and cleansweep but just wasn't feeling it so after wasting a lot of time and some money I did just as you mentioned and started from scratch. Much happier now.

Also, plan your amp placement ahead of time - this part I did right. If you plan on putting them under the rear seats not everything will fit...like a JL 500/5. Ended up with two amps smaller in size - one on each side on floor against back wall. JL 300/4 & 250/1 fit real nice. Just sayin.

 

i have the basic radio not the alpine, what is the biggest amp you can place back there? would love to be able to measure but in Iraq at the moment

 

I only looked at the JL slash series and those fit nice. The 450 wouldn't though. If you go to jlaudio.com you can see the size differences between the 250, 300 and the 450, 500's. That should give a good idea. There is a little more space but the 450/500 won't fit because of their length and the brackets for the middle seat.

 

The easiest way to do this is to visit pac-audio.com and get the right part number need to add RCA outputs from the stock head unit. The part plugs right into your factory harnesses with no splicing. It gives you front/rear outputs and also gives you a remote wire (which is a good deal considering the CAN bus communication our truck uses). I tried the splicing deal and this is much easier. Kind of pricey though, the part was about $100.