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 RX-7 Base, StandardFACTORY OEM SERVICE PROCEDURE

Circuit Opening Relay

With relay connected, ensure specified voltage is present at relay terminals. See FUEL PUMP RELAY CIRCUIT VOLTAGES table. For locations of circuit opening relay, see CIRCUIT OPENING RELAY LOCATIONS table.

CIRCUIT OPENING RELAY LOCATIONS

Application	Location
B2600i & 929	Behind Left Kick Panel
Miata	Under Dash, Left Of Steering Column
MPV	Mounted On ECU, Under Protective Cover On Passenger Side's Floor
MX-6 & 626	On Fuse Block
Protege & 323	On Passenger Side's Wall, Near ECU
RX7	On Bracket Behind Instrument Panel

FUEL PUMP RELAY CIRCUIT VOLTAGES

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

If voltages are okay, remove relay from vehicle. Check relay operation using a 12-volt battery source and perform resistance tests. See Fig 1 .

Fig 1: Testing Fuel Pump Relay

Courtesy of MAZDA MOTORS CORP.

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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