Were is the fuel pump ground wire located on 1985 Oldsmobile delta 88?

There isn't one single, universally-located ground wire for the fuel pump on a 1985 Oldsmobile Delta 88. The ground path is usually achieved through the chassis. The fuel pump's ground is typically established through its mounting point on the fuel tank, which is grounded to the car's body.

To troubleshoot a fuel pump ground problem:

* Check the fuel tank's straps: Ensure the straps holding the fuel tank are clean and making good metal-to-metal contact with the car's body. Corrosion is a common culprit. Clean these connections with a wire brush.

* Inspect the wiring harness: Look for any broken or corroded wires near the fuel tank or the fuel pump relay.

* Test the ground at the fuel pump itself: Disconnect the fuel pump wiring harness. Use a multimeter to test for a good ground at the pump's mounting point and at the connector itself. You should have a near-zero resistance reading between the pump's mounting point and a known good ground point on the car's chassis (like a bolt on the engine block).

* Check the fuel pump relay: A faulty relay can sometimes manifest as a grounding issue.

Instead of searching for a specific "ground wire," focus on ensuring a good ground path from the fuel pump to the car's chassis. If you've checked all of the above and still have a problem, you may have a more serious electrical fault requiring professional diagnosis.