Fuse & Circuit Breaker Identification

1991 Pontiac Firebird Formula, 5.0 F, Standard, M39SECTION Fuse & Circuit Breaker Identification
  • 1 - 10 Amp (Red) -  Computer Command Control
  • 2 - 10 Amp (Red) -  Fuel Pump, Oil Pressure Switch, Electric Cluster (1987-89)
  • 3 - 3 Amp (Violet) -  Crank Signal To ECM
  • 4 - 20 Amp (Yellow) -  Choke Heater (Engine Code H) (1983-87), Cooling Fan Relay (Engine Codes F & S)
  • 5 - 20 Amp (Yellow) -  Turn Signal Lights, Back-Up Lights
  • 6 - Blank (1983-86), 20 Amp (Red) -  MPFI Injectors (Engine Codes F & S)
  • 7 - 20 Amp (Yellow) -  Parking Lights, Side Marker Lights, Taillights
  • 8 - 25 Amp (White) -  Heater &/Or Air Conditioner
  • 9 - 10 Amp (Red) -  Audio Alarm System, Computer Command Control (1983-86), Vehicle Speed Sensor (1987-89), TCC Brake Switch, Cruise Control, A/C Relay, Gauges, Rear Window Defogger
  • 10 - Blank (1983-86), 20 Amp (Yellow) -  MPFI Injectors (Engine Codes F & S)
  • 11 - 20 Amp (Yellow) -  Glove Box Light, Cigarette Lighter, Hatchback Lid Release, Horn Relay, Interior Lights, Power Antenna, Power Door Locks, Radio/Digital Clock, Computer Command Control
  • 12 - 5 Amp (Tan) -  Instrument Panel Lights
  • 13 - 10 Amp (Red) -  Radio
  • 14 - 25 Amp (White) -  Windshield Wiper/Washer
  • 15 - 35 Amp (Circuit Breaker) -  Power Windows, Rear Wiper/Washer
  • 16 - 35 Amp (Circuit Breaker) -  Power Door Locks, Power Seats, Rear Window Defogger
  • 17 - 20 Amp (Yellow) -  Stoplight Switch, Hazard Flasher, Chime
RENDER: 1.0x

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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.