2001 Toyota 4Runner Car Audio Wiring Diagram Whether your an expert Toyota 4Runner mobile electronics installer, Toyota 4Runner fanatic, or a novice Toyota 4Runner enthusiast with a 2001 Toyota 4Runner, a car stereo wiring diagram can save yourself a lot of time. Automotive wiring in a 2001 Toyota 4Runner vehicles are becoming increasing more difficult to identify due to the installation of more advanced factory oem electronics. 2001 Toyota 4Runner OE Wiring Harnesses & Stereo Adapters Toyota 4Runner 2001, Aftermarket Radio Wiring Harness by Metra®, with OEM Plug. For aftermarket stereo. Metra preassembled wiring harnesses can make your car stereo installation seamless, or at least a lot simpler.