Here are a few items that I found helpful with my car and I am sure you can too.
Electrical wiring diagram for both 01 and 02+
Installation Manual for the SRT Stage 2.75 Turbo Kit IS300
2002-2005 Wiring Diagram Complete
2002+ IS300 Engine to Body Plugs EA1 EA2 EA3 Pinout
2002+ IS300 Junction Connector J1, J2 Pinouts
2001-05 Diagnostic & Wiring & TSB Manual
