How to Check Fuses Without Removing Them by Using a Test Light

Time needed: 5 minutes.

Steps to Check Fuses

1. Find the Fuse

   Find the fuse box and remove the fuse box cover. Fuses can be located in different areas, like inside the car on the driver side and in a fuse box under the hood. If you’re having a problem with the interior lights, for example, find the fuse for this part on the diagram on the back of the fuse box cover.

2. Test the Test Light

   Clip the end of the test light to the negative battery terminal and press the tip to the positive battery terminal. Press the end of the test light to the terminal and see if it lights up.

3. Test the Fuse with a Test Light

   You can check if the fuses are blown without a need for removing them by using a test light. Press the test light to the pin on one end of the fuse and make sure the test light illuminates. Then press the test light to the pin on the other end of the fuse and make sure the test light lights up. If the test light lights up at both ends of the fuse, the fuse is working and is in good condition. If the light does not light up on one side of the fuse, it’s blown. You’ll needs to replace it and diagnose the cause further.
   
   Tip: Fuses generally don’t blow without a cause, like a broken wire or motor.
   
   Tip: If the fuse does not light up on either end, it does not mean the fuse is blown but that there’s no power going to the fuse. The item may need the key to be on or in accessory mode for the fuse to have power.

4. To Inspect the Fuse Further, Remove It

   Remove the fuse from the fuse box. Look for a broken wire inside the fuse or a discolored surface which are signs the fuse is blown and you’ll need to replace it.