1. Check the Fuse:
* Locate the fuel pump fuse: Consult your owner's manual to find the location and amperage rating of the fuel pump fuse. It's often in the underhood fuse box, but sometimes in the interior fuse panel.
* Inspect the fuse: Check for a blown fuse (broken filament). Replace it with a fuse of the *same amperage rating*. Don't use a higher amperage fuse – this could cause a fire.
* Test the fuse: If the fuse is good visually, use a multimeter to confirm continuity (a good fuse will show near zero resistance).
2. Check the Fuel Pump Relay:
* Locate the relay: Your owner's manual will show the location of the fuel pump relay. It's typically in the underhood fuse box.
* Visually inspect the relay: Look for any obvious damage.
* Swap the relay: If possible, swap the fuel pump relay with a known good relay of the same type (often, you can swap it with a similar-looking relay temporarily – just be sure to put it back!). If the problem moves (power to the pump now exists), the original relay is faulty.
* Test the relay: Use a multimeter to test the relay for continuity and correct switching behavior (refer to a relay testing guide online for your specific relay).
3. Check the Wiring:
* Power wire: Trace the power wire from the fuse to the fuel pump. Look for breaks, corrosion, or loose connections in the wiring harness. A multimeter can be used to test for power at different points along the wire.
* Ground wire: Check for a good ground connection at the fuel pump. A poor ground can prevent the pump from working. Clean the ground connection if necessary.
* Inertintial Switch (sometimes called a Crash Sensor): Some vehicles have this safety device which cuts power to the fuel pump in a collision. Check to make sure it's not triggered and hasn't malfunctioned.
4. Check the Fuel Pump Inertia Switch:
* This is a safety device to prevent fuel leaks in a crash. It's usually a small, usually red, button located somewhere under the dash or in the engine bay (check your owner's manual).
* Press the button to reset the switch. If the problem is solved, the switch may be faulty and needs replacement.
5. Check the Fuel Pump itself (least likely cause, but still possible):
* Test the pump directly (advanced): This is done by bypassing the wiring and applying 12V directly to the fuel pump terminals. *Caution:* This is only recommended if you know what you're doing as it could be dangerous. You'll need a wiring diagram and suitable safety precautions. It only proves the pump itself is bad if it works when tested this way.
6. Consult a wiring diagram:
A wiring diagram specific to your 1993 S-10 2.8L is invaluable. It will show you the exact path of the power wire, the location of all components, and help you systematically troubleshoot the problem. You can usually find these online through repair manuals (like Chilton or Haynes) or some automotive websites.
Important Safety Note: Work on fuel systems can be dangerous due to the flammability of gasoline. Always disconnect the battery negative terminal before working on any fuel system components. Ensure proper ventilation and avoid sparks or open flames. If you're not comfortable performing these checks, take your vehicle to a qualified mechanic.
