How To Check Fuses

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The fuse is the most common method of an automotive wiring circuit protection.

Whenever there is an excessive amount of current flowing through a circuit the fusible element will melt and create an open or incomplete circuit. Fuses are a one time protection device and must be replaced each time the circuit is overloaded.

To determine if a fuse is open (See Picture Below), remove the suspected fuse and examine the element in the fuse for an open (2). If element is not broken (1) then the fuse is good, also check for continuity using a Digital Multi Meter or a Test Light. If the element is open or continuity is suspect, replace the fuse with one of equal current rating.

How To Test Fuses
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Checking fuses

Amp Ratings Colors For Fuses

Mini Fuses

  • 2 Amps- Gray
  • 3- Violet
  • 5- Tan
  • 7.5- Brown
  • 10- Red
  • 15- Blue
  • 20- Yellow
  • 25- White or Natural
  • 30- Green

Maxi Fuses

  • 20 Amps- Yellow
  • 30- Light green
  • 40- Orange or Amber
  • 50- Red
  • 60- Blue

J- Case Fuses

  • 20 Amps- Blue
  • 30- Pink
  • 40- Green
  • 50- Red
  • 60- Yellow