* Under the hood in the Power Distribution Center (PDC): This is the most common location. The PDC is a large fuse and relay box, often located near the battery. You'll need to consult your owner's manual or a wiring diagram specific to your van's year and engine to identify the correct relay. The relay itself might be labeled, but not always clearly.
* Under the dash: Less common but possible, particularly on models with different electrical configurations.
To find it:
1. Consult your owner's manual: This is your best bet. It should have a diagram of the fuse and relay box(es).
2. Use a wiring diagram: A wiring diagram specific to your 1992 Dodge B350 van (including engine type) will show the relay location and circuit. You can often find these online through automotive parts websites or repair manuals.
3. Visual Inspection (PDC under the hood): Carefully examine the Power Distribution Center. Relays are usually square or rectangular and will often have a diagram on the cover indicating what each relay controls. Look for relays that are of a similar size and shape. If you can identify any relays connected to the fuel system (fuel injectors, etc.), it is likely the fuel pump relay will be in the same general vicinity.
4. Use a multimeter: If you're comfortable with basic electrical work, you can use a multimeter to trace the fuel pump circuit. This is a more advanced method but can pinpoint the relay.
Important Note: Before attempting any work on the electrical system, disconnect the negative terminal of your battery to prevent accidental shorts or damage. If you're not comfortable working with automotive electrical systems, it's best to consult a qualified mechanic.
