Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1991 Mazda 929 BaseFACTORY OEM SERVICE PROCEDURE
Fuel Pump Relay (NAVAJO)
- Remove fuel pump relay (located under power distribution box on right inner fender). Connect 12 volts to terminal "C" and ground terminal "D". Check for continuity between terminals "A" and "B". If continuity is present, relay is okay. If continuity is not present, replace relay.
- Turn ignition on. Ensure 12 volts present on Red and Black/Yellow or Yellow wires. If 12 volts is not present, repair circuits from Electronic Engine Control power relay, battery or power distribution box.
- Connect 12 volts to terminal "A". Fuel pump should operate. If not, repair wiring to inertia switch, fuel pump, fuel pump ground, or replace fuel pump.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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