Completely bypass the front amp and remove the factory amp. Run speaker wire for your speakers front and rears directly to the radio and bypass the amp located in the passengers kick panel.
For the sub run a 6' ft RCA cable from your head unit to the factory amp location. Connect the RCA cable to the subwoofer output of your head unit using the RCA cable you ran on the other end at the factory amp location you will cut off the head of the RCA cable you ran, strip the wire the center conductor of each wire known as the tip will connect to pin 12 and 13 at the connector C2054, the shield known as sleeve of both channels left and right connect together and connect to pin 10 at the connector C2054.
Make sure to remove the factory amp and connect your front and rear speakers from the head unit directly to connector C2054 and subwoofer RCA connection from the head unit directly to connector C2054 using the 6' ft RCA cable that will run. This method will eliminate any issues of engine whine as you are not externally amplifying any audio signals with this method. Engine noise happens when the line level signal are amplified by an external amplifier and has unmatched signal level. You are always better off installing the aftermarket radio as it was designed for direct aftermarket radio to speakers or aftermarket radio to aftermarket amp vs. trying to make mismatch components work together sometimes you can get lucky and it works with factory amps but require more parts to math the signal cost more and not always the best solution.

 

That is what I needed to know! I will wire it up this weekend. Thanks for your help!

 

When wired as described above the front and rears work excellent, however the sub does not. If I use both of the pre-amp sub RCA's as described above then the sub is off, but if I only use one of the RCA's the sub works, and the RCA connected to 13 is notably more powerful. What should I do? Also, the sub from the amp is displaying the same type of noise that the stock front amp was before it was removed. You say that no engine noise will occur because nothing is being externally amplified but the sub still is right?

 

Wow. Thank you for sharing!

 

I ran into the same issue that Diamondback ran into and thought I'd post my solution in case someone else ever runs into it as well. (also wanted to add that this thread was insanely helpful and I couldn't have done this project without it!). Basically the issue is (and sorry, i'm not very techincal so hopefully i'm explaining this right) that the Subwoofer is mono but most modern head units have stereo outputs for their subs. so if you do the RCA trick described above, you end up using two positives where you should have been using a positive and a negative. To overcome this, I put my two pin wires together to make a mono positive and put my two shield wires together to make a mono negative and then put the positives on the red wire (13) and the negatives on the black wire (12) of connector 2054. Honestly I didn't know what to do with the shield wire (10) so I just left it and it worked fine. If anyone knows anything more to do with that shield wire please let me know but I'm very happy with my new stereo upgrade and bypassing the main amp and leaving the sub amp with this configuration worked great.

 

DiscoD,

Thank you so much, that works perfectly.