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.
1988 Mazda 929 AutomaticFACTORY OEM SERVICE PROCEDURE
Circuit Opening Relay
- Remove circuit opening relay. Check circuit opening relay circuits with CIRCUIT OPENING RELAY TERMINAL CIRCUITS
table.CIRCUIT OPENING RELAY TERMINAL CIRCUITS
Terminal Condition Results Fp Resistance to Ground 0.2-30 Ohms Fc Resistance to Ground (Cranking) Infinite B Voltage to Ground (Ign. On) Battery Voltage STA Voltage to Ground (Cranking) Approx. 9 Volts E1 Resistance to Ground Infinite - With circuit opening relay removed, apply 12 volts to terminal STA of relay. Ground terminal E1. Ensure there is continuity from relay terminals B to FP. See Fig 1 .
- Apply 12 volts to terminal B of relay. Ground terminal Fc. Ensure there is battery voltage at relay terminal Fp.
- Ensure that relay has correct resistance between terminal with CIRCUIT OPENING RELAY RESISTANCE table.
CIRCUIT OPENING RELAY RESISTANCE
| Terminals | Resistance |
|---|---|
| STA to E1 | 15-30 Ohms |
| B to Fc | 80-150 Ohms |
| B to Fp | Infinite |
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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