To find it definitively:
1. Consult your owner's manual: This is the best source of information, as it will show you a diagram of your specific vehicle's fuse box(es) and relay locations.
2. Look for the underhood fuse box: This is usually a black plastic box located near the battery. Open the box and look for a diagram on the inside cover. The diagram should identify the fuel pump relay. It might be labeled "Fuel Pump," "EFI," or have a symbol depicting a fuel pump.
3. Check the interior fuse box (if necessary): If you can't find it under the hood, look for a fuse box under the dashboard, usually on the driver's side. Again, check the cover for a diagram.
4. Use a wiring diagram: If you're still having trouble, you can find a wiring diagram specific to your 1995 Chevy Blazer's engine (e.g., 4.3L, 5.7L) online or at an auto parts store. This will show you the relay's location and the circuit it controls.
Without the specific engine size and trim level of your 1995 Chevy Blazer, a more precise location can't be given.