To find the fuse you're looking for, you need to:
1. Consult your owner's manual: This is the best place to start. The manual will have a fuse box diagram showing the amperage and purpose of each fuse.
2. Locate the fuse boxes: 1998 Blazers typically have multiple fuse boxes, one under the hood and one inside the vehicle (often under the dashboard).
3. Identify the circuit: If you know what the circuit is for (e.g., power windows, power seats), the owner's manual should tell you which fuse protects it.
Without knowing *what* circuit is blowing a 50 amp fuse (or if that is even the correct amperage) it's impossible to give you the specific location. Simply searching for a 50-amp fuse is not sufficient. A blown fuse often indicates a short circuit that should be addressed, not just replaced.