AlliexWond

Okay so a buddy of mine has a 1994 Lexus sc400. I've got the head unit to power on but am having difficulty with connecting the speakers. I can not for the life of me figure out these wires. I have installed many after market systems as a hobby and no matter where I look, I can not find the radio wire code for the speakers. Should I just over ride the whole wiring harness(other than the power. Constant and ground) and run new speaker wires directly to the head unit? I've found ones for the front right and rear but they don't put out any sound. All speakers are pioneer, along with the head and the amp is 1200w with 2 12”subs. Any help would be greatly appreciated. I'm getting extremely frustrated and starting to hate Lexus lol.
-Allie

AlliexWond

I meant to say front right and front left, not rear speakers.

YotaSC400

The factory sound system uses a common ground for all speakers, since most aftermarket head units don't support a common ground you will probably have to run your own speaker wiring.

pogoism9

iTrader: (1)

The metra harness should be fine for you if you aren't trying to keep your old amp.

YotaSC400

https://www.clublexus.com/forums/lex...b-working.html

tsmith1315

Front speaker wires can be accessed behind the carpet where they go into the doors. There's a large molex-style connector containing all of the door wiring there. Standard Toyota colors, IIRC. I clipped them and ran wires from there to the new head unit. To verify colors, you can pull the window switch out and you'll see the speaker wires through the hole.

Rear speaker wires will be in the trunk, as they go directly from the amp to the speakers. It would be simplest to run new wires all the way for the rears.

The signal-level wiring from the head unit to the amp may be common ground, but the speaker signals from the amp are not.

jimmymac30

iTrader: (8)

i followed the same link listed above. Make a wiring loom that runs from your new head unit harness all the way to the trunk. There is a connector that goes into the factory amp. Splice your new wires in to the existing harness to bypass the factory amp.