2GS factory amplifier integration, help??

Hey guys I'm doing a pretty small install for the wifey's GS.  I've searched all over the internet for days now and can not seem to find a pre-made harness for the factory amplifier integration.  Can anyone here clue me in on my options?  I'm hooking up an Alpine w505 to stock speakers...  All help would be appreciated.  

thanks

what year?

1998 GS300.

should I bypass the factory amp and power off the HU?  I'm not looking to add in any amplifiers.  Initially I was looking just for factory amplifier integration

is it the nakamichi system or the standard? without oem navi i'm assuming.

right, sorry.  non nakamichi.  as I continue my search it's starting to look like my best is to just power the speakers from the HU and upgrade sub and add sub amp.

that will definitely make things easier, but it looks like you have some work cut out for you on the car harness side as well. have you looked at your connection yet? from what i am seeing there is not a 100% harness but something that could work depending on whether it's a 16 or 20 pin connector.

at this point i would power the full range speakers from an aftermarket amp as well.

You need to make a line converter. I'll find the thread on club lexus and link it later.

[URL]http://www.clublexus.com/forums/lexus-audio-video-security-and-electronics/330497-how-to-hook-up-amp-and-woofer-with-stock-stereo.html[/URL]
 
 
Then again, this is for hooking up an aftermarket amp to the stock HU...maybe it'll help out someway.