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.
1994 Mazda MX-5 Miata Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Circuit Opening Relay
- With relay connected, ensure specified voltage is present at relay terminals. See CIRCUIT OPENING RELAY CIRCUIT VOLTAGE table. For location of circuit opening relays, see CIRCUIT OPENING RELAY LOCATION table.
- If voltages are okay, remove relay from vehicle. Check relay operation using a 12-volt battery source and perform resistance tests. See Fig 1 .
CIRCUIT OPENING RELAY LOCATION
| Application | Location |
|---|---|
| Miata | Under Dash, Left Of Steering Column |
CIRCUIT OPENING RELAY CIRCUIT VOLTAGE
| Terminal | Ignition ON: Volts | Ignition START: Volts | Idle Volts |
|---|---|---|---|
| Fp | 0 | 12 | 12 |
| Fc | 12 | 0 | 0 |
| B | 12 | 12 | 12 |
| STA | 0 | 12 | 0 |
| E1 | 0 | 0 | 0 |
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.