I did a search and I couldn't find any remote output from a wrx 04 stereo. I have my amplifier(1000wts so is noisy with the stereo off) remote set to the acc cable on the stereo, but I'll like to have a remote output so when my stereo is off the amplifier too. Anyone done some tipe of remote conection for the amplifier?

Search scoobymods...I believe they have a pic of the stereo wiring harness on there.

it's a blue wire with a white strip isn't it?

There is a remote wire that switches power for the antenna amplifier on the 04+ with the antenna in the rear window. However this wire may only have power when in radio mode and not in CD mode, which would make it unsuitable for switching an amp. I'm not sure about this, but I do recall seeing it stated someplace in the past.

Why is your amp noisy? That statement needs more clarification...

The cable you are mentioning is a white cable num. 14 it got power only when the stereo is on AM/fm mode not on CD/cassete. I did search scoobymods and I can find nothing else. I also used my voltmeter to test every single cable and no luck. But there got to be a way, a bypass or something. Yes it is noisy when stereo is off, because the amplifier still on sending watts to the speakers, I got a ground insulator and it help a bit, but if I can turn the amp off when I turn my head unit off it will be perfect.

... no luck. But there got to be a way, a bypass or something.Nothing from the stock radio. Your only options are to add a switch, or use an after-market radio that has an amp remote line. Or maybe some company out there makes a small "black box" that listens to the speaker outputs from the radio and creates a remote control line for your amp.

See this thread for more information...
Stock head unit information -- pin-outs, aux inputs, and more (http://forums.nasioc.com/forums/showthread.php?t=749402)

(There are links to that thread from the Car Audio Video forum's "sticky" FAQ threads)

Thanks if I find something else I'll let you Know.