* Integrated into the distributor: If your Silverado has a distributor (most likely with a TBI or older fuel injection system), the ignition module is *inside* the distributor. You won't be able to easily replace it separately; you replace the whole distributor.
* Separate module: On some models (particularly those with a later style fuel injection system), there might be a separate ignition control module (ICM). This would typically be mounted on the firewall near the distributor or sometimes under the hood, but its precise location can vary.
To find it:
1. Identify your engine: Check your vehicle's documentation or the engine bay for an engine code (usually a combination of letters and numbers).
2. Consult a repair manual: A repair manual specific to your 1994 Chevy Silverado's year, make, model, and engine will show you the precise location of the ignition module (or distributor). A Haynes or Chilton manual are good options.
3. Search online: Use a search engine like Google, adding your engine code to the search terms ("1994 Chevy Silverado [Engine Code] ignition module location"). Look for images and forums related to your specific vehicle.
Without knowing the engine type, providing a definitive location is impossible. A repair manual is your best bet for accurate information.