To find the relevant fuse or relay, you must consult your owner's manual. The manual will have a fuse/relay box diagram showing the location and what each fuse or relay controls.
If you don't have the manual, you can try these steps:
1. Locate the fuse boxes: There are usually several fuse boxes in a 1991 Silverado. One is typically under the hood, and another might be located inside the cab, often under the dash.
2. Examine the fuse box diagrams: The fuse box cover usually has a diagram showing which fuse controls which circuit. Look for a fuse or relay labeled "fuel pump," "EFI," or something similar. If the diagram isn't clear, look for a fuse with a high amperage rating (likely a larger fuse than others).
3. If you can't find it in the fuse boxes, look for a fuel pump relay: This is more likely than a direct fuse for the fuel pump. Relays are usually larger than fuses.
Without your owner's manual, pinpointing the exact location is impossible. Remember, working with automotive electrical systems can be dangerous. If you're not comfortable doing this yourself, take your truck to a qualified mechanic.
