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.
1978 Mazda Cosmo Automatic TransFACTORY OEM SERVICE PROCEDURE
1978-79 RX7
- Disconnect wiring from relay. With no power applied, continuity should exist between terminals No. 1 and 2, No. 4 and No. 2, and terminals No. 4 and 1. No continuity should exist between terminals No. 3 and No. 2, or terminals No. 3 and 4.
- Connect battery positive lead to terminal No. 6 and negative lead to terminal No. 5. Continuity should exist between terminals No. 3 and 2, and between terminals No. 4 and 3. No continuity should exist between terminals No. 1 and 2, No. 4 and 2, or terminals No. 1 and 4. If relay does not test as described, replace it.
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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