I have a 1995 Toyota Celsior which appears to be the same as a 1996 usdm lexus ls400. I'm trying to install a aftermarket double din radio but I'm having trouble with the wiring. I've spent hours searching online trying to find a harness but it appears they don't make them. I can only find them for a 90-94. Mine has the basic pioneer premium sound head unit and its not a nakamichi or nav or anything. I can't find a wiring diagram to tell me what wires are what either. Also, does anyone know if I can use a line output converter and splice a rca lead to the positive and negative of the subwoofer wires to retain use of the factory subwoofer like you can on the 90-94 models?

 

You are trying to use the factory amp? Have tried on other Lexus amps (other years to be exact) I found the output of the head unit was not high enough to satisfy the amplifier, this was a head unit with 5 volt pre outs. Check out this thread should help you
https://www.clublexus.com/forums/ls-...-diagrams.html

Wire colours for this era of Lexus are mostly uniform, speaker and power. But of course verify don't assume.