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.
1990 Mazda MPV 3D Van Wagon, 3.0 2, AutomaticFACTORY OEM SERVICE PROCEDURE
Test D: Main Switch Operates, But Sub-Switch Does Not Operate Power Window
- Turn ignition on. Turn power-cut switch on main switch to ON position. Check voltage at Black/Blue wire terminal of main switch connector. If battery voltage is present, go to next step. If battery voltage is not present, check power-cut switch portion of main switch. See MAIN SWITCH under COMPONENT TESTS.
- Check voltage at Black/Blue wire terminal of sub-switch connector. If battery voltage is present, check sub-switch. See SUB-SWITCH under COMPONENT TESTS. If battery voltage is not present, repair wiring harness between main switch and sub-switch. See WIRING DIAGRAMS .
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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