Alternator 78-85 Fiat 124 Spider

Starting with the 1979 model year, the Fiat 124 Spider comes standard with an alternator that includes an integrated electronic voltage regulator.

Guideline values for charging voltage:

• Engine off: 12.4–12.8 V
• Idle: 13.8–14.4 V
• 2,000–3,000 rpm: 13.8–14.5 V

Attention:

• Below 13.5 V → The battery is not charging sufficiently. Possible causes include a faulty regulator, worn carbon brushes, a faulty alternator, or poor cable or ground connections.
• Over 14.8 V → The built-in voltage regulator is likely defective and should be replaced. On many Bosch alternators, the regulator—including the carbon brushes—can be replaced separately without having to replace the entire alternator.

Tip: The charging voltage is always measured directly at the battery terminals. This is the only way to get a reliable measurement of the alternator’s actual charging power.