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.
1991 Ford Probe GL, AutomaticFACTORY OEM SERVICE PROCEDURE
Regulator Power Source Test
NOTE:
Alternator wiring plug must be disconnected for the following test.
- Disconnect alternator wiring plug. Turn ignition switch to ON position (engine not running). Connect positive voltmeter lead to alternator "S" terminal at rear of alternator. See Fig 1. Connect negative voltmeter lead to alternator rear housing.
- If reading is same as battery voltage, proceed to ROTOR FIELD COIL TEST. If reading is less than battery voltage, problem is indicated between terminal "S" wire and battery.
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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