Replaced Bose system

I replaced all my bose speakers with Infinity kappas in my new car and also replaced the Bose amp with RF Punch P4004- 50Wx4. My problem is everytime i try to use channels 3 & 4 I lose power on the speakers. I tapped on the Bose HU ( low level signal) by splicing RCA plugs to get signals to my amp.  I think all my wirings are good because I can use either Fronts or rears on a 2ch setup but once I use all 4 I lose power. Pls help ..

 Sorry about that......

What I meant by channel 3 & 4 is the other 2 ch in ( either front or rear). I spliced the line output wires behind the Bose HU and turned it to 2 female RCA connectors and use that to get signal to the amp. I believed those outputs are already in low signal so i did not use any LOCs. The amp is brand new and I also tried using my old audio legacy  4ch amp and the same thing happened. It don't go to protection mode or kill sound, but everytime I try to plug the signal wires (RCA) to either front ch or rear ch it goes Mono hence losing power. I replaced all the factory wires. Thanks for your quick reply....hopefully this helps explaining it a little bit more.

Is this a mazda or Gm vehicle?

It is not impossible to replace the headunit, it is just hella costly. Most Bose systems in the newer Mazda vehicles have a different preout voltage on the rear (lower) than the front (higher). Double check the gains on the amplifier.

That said, disconnect the speakers from channel 1&2 as well as the rca's.  Connect the channel 1&2 rca to the 3&4 input. Connect the channel 1&2 speaker leads to the channel 3&4 output. This is going to verify that the amp is working. If this works, disconnect the rca's and plug in the other pair. If it still works, disconnect the speaker wires and replace with the other pair. Post up the results.

You can get the dash piece customized with fiberglass at a local shop , ,but ofcourse its gona be like $300.

Someone did such a thing on this site.   Go to the Fiberglass forum and do a search, , he showed a step by step, , you could do it if your mechanically inclined.

forbiiden,

Disconnected both 1 & 2 speakers and rca's and  connected them both to the amps 3 & 4 inputs and outputs and it works great.

Disconnected speakers and rca's and replaced them with the other pair ( both speaker wires and rca's) and connected them to the amps 3 & 4 inputs and outputs and they work great.

Did the same thing on channels 1 & 2 and everything works fine but as soon as I try to use all of them for a 4 ch setup I ended up with the same problem ( system distorted and/or losing power). I also used my old amp from my other car and Im getting the same problem. Do i need to buy a line driver of some sort to boost the signal coming out from the Bose HU ( i know its low level but im not sure about the voltage)?