To find it:
1. Locate your fuse box/Power Distribution Center (PDC): This is usually under the hood, often near the battery. It's a large box with numerous fuses and relays. It might be labeled "PDC," "Fuse Box," or have a similar designation.
2. Consult your Jeep Wrangler's owner's manual: The owner's manual should have a diagram of the fuse box showing the location of the relays. Look for relays related to the fuel pump or fuel injection. They might be labeled as such or with a more general description like "engine control" or a related function.
3. Check online resources: Websites dedicated to Jeep Wranglers (like Jeep forums) often have diagrams and discussions about relay locations for specific engine types. Searching for "1990 Jeep Wrangler [4.2L or 2.5L] fuel pump relay" or "fuel injection relay" should yield helpful results.
4. Visual inspection: Once you have an idea of which relay it might be (from the manual or online), carefully inspect the relays in your PDC. Some might have markings, or you may be able to trace wires to determine their function. Be cautious when working around electrical components.
Important Note: Incorrectly identifying and manipulating relays can damage your vehicle's electrical system. If you're unsure, it's best to consult a qualified mechanic.
