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Home >> Ford >> 1978 >> Fiesta >> Repair and Diagnosis >> Electrical >> Charging Systems >> Alternators & Regulators - MOTORCRAFT With Separate Regulator >> Testing >> Test Results

Test Results

  1. If voltmeter reading indicates over-voltage (more than two volts above battery voltage), shut off engine and check ground connections between regulator and alternator and/or regulator and engine. Clean and tighten connections, then repeat tests.
  2. If over-voltage condition still exists, disconnect regulator wiring plug and repeat test. If condition is corrected, replace regulator and repeat test.
  3. If over voltage still exists with regulator disconnected, a short is indicated in wiring harness between alternator and regulator. Repair short circuit, then replace voltage regulator and repeat tests with regulator plug connected.
  4. If voltmeter reading does not increase at least one volt, check for presence of battery voltage at alternator "BAT" terminal, and at regulator plug "A" terminal. If no voltage is present, an open wire is indicated. Repair wire and repeat tests.