Electrical system
Electrical system is an overview of the electrical systems used in the Pontiac Fiero.
The Fiero electrical system includes the battery, charging system, starting system, lighting, gauges, fuses, relays, grounds, engine control wiring, body wiring, and model-specific circuits.
Overview
Many electrical problems on the Fiero are caused by age, corrosion, poor grounds, worn connectors, damaged wiring, failing relays, or previous owner modifications.
Because the Fiero is now several decades old, electrical diagnosis should usually begin with inspection of grounds, connectors, fuses, relays, battery condition, and charging voltage.
Major components
Lighting
- Headlights
- Headlight motor problems
- Gen 1 headlight system
- Gen 2 headlight system
- Tail lights
- Brake lights
- Turn signals
- Interior lights
- Instrument cluster lights
Gauges and instruments
- Instrument cluster
- Temperature gauge
- Fuel gauge
- Oil pressure gauge
- Tachometer
- Speedometer
- Warning lights
Common electrical topics
- Ground problems
- Battery drain
- Charging system problems
- No-start diagnosis
- Starter problems
- Headlight motor problems
- Instrument cluster problems
- Tail light problems
- Power window problems
- Power lock problems
Engine control and diagnostics
The Fiero uses an electronic engine control system. Diagnostic information can be accessed through the ALDL connector.
Related topics:
- ECM
- ALDL diagnostics
- Diagnostic trouble codes
- Sensors
- Ignition module failure
- Fuel pump relay
- Check engine light
Model-year differences
Electrical systems vary by model year, engine, options, and trim level. Some important differences include the 1984 wiring layout, later V6 wiring, and the change from the first-generation to second-generation headlight system.
Related topics:
- 1984 wiring
- 1985 wiring
- 1986 wiring
- 1987 wiring
- 1988 wiring
- Gen 1 headlight system
- Gen 2 headlight system