Syncing a Real Guitar to Guitar Hero 3 Wii? Not Possible

You cannot sync a real guitar to Guitar Hero 3 on Wii.

The game uses a proprietary wireless guitar controller designed specifically for it; it cannot detect signals from a real guitar.

Alternative Approaches

• Adapters: Some third-party adapters connect real guitars to consoles via pickups and software, but setup is complex, expensive, and not guaranteed to work with GH3.
• Music Software: Import GH3 song files into music programs to play on a real guitar—different experience, but authentic.

No direct connection possible; explore alternatives if you want to use a real instrument.