2003 Toyota Tundra OE Wiring Harnesses & Stereo Adapters Toyota Tundra 2003, Aftermarket Radio Wiring Harness by Beat-Sonic®, with OEM Plug. Includes 10-Pin and 6-Pin Stereo Connectors. Stereo wiring harness for vehicles without factory amplifier systems. 2003 Toyota Tundra Stereo Wiring Harness - autozone Equip cars, trucks & SUVs with 2003 Toyota Tundra Stereo Wiring Harness from AutoZone. Get Yours Today! We have the best products at the right price.