* Under the hood in the fuse box: This is the most common location for many GM vehicles of that era. The fuse box is usually located near the battery. Check the fuse box diagrams inside the lid for a relay labeled "fuel pump," or look for a relay that is visibly connected to the fuel system.
* Under the dash: Less common, but some models placed relays under the dashboard in a separate fuse/relay panel.
* In the under-hood relay center: Some G20s had a separate relay center, often mounted on the inner fender.
To find it definitively:
1. Consult your owner's manual: This is the best source of information. It should have a diagram of the fuse box and relay locations.
2. Check the fuse box diagrams: Even without the owner's manual, there are often diagrams printed inside the fuse box lid showing what each fuse and relay controls.
3. Use a wiring diagram: A wiring diagram specific to your 1989 Chevrolet G20 van (you'll need to know the engine size and any other relevant options) will show you precisely where the fuel pump relay is and how it's wired. These diagrams can often be found online through repair manuals or specialized automotive websites.
4. Search online forums: Websites and forums dedicated to Chevrolet G20 vans might have discussions about fuel pump relay locations from other owners. Be sure to specify your exact year, engine, and trim level.
Without knowing your specific G20's configuration, it's impossible to give a precise location. Systematic checking of the locations mentioned above, guided by your owner's manual or a wiring diagram, is your best bet.
