Tuesday, March 29, 2011

REPLACING FUSES

How To Replace A Blown Fuse

If you own a car, there’s a chance one of the fuses in your car, truck or SUV will blow out. When that happens, the results don't usually create a crisis, but it means that something on the vehicle is no longer working.  Most likely, the thing that'll quit working on your vehicle will be relatively minor. It could be the backup lights, the turn signals, the high-speed setting in the climate control system's fan, the radio, or even the interior lights. Whatever the case, if a fuse blows, the device in question won't work.

For exterior or interior lighting, the possibility of a fuse being the cause of malfunction is quite likely. In fact, for any single item or system in the vehicle, the chances of a fuse being the cause of an electrical failure is high enough that, in most cases, it should be the first thing you check.

After reading this post on fuse inspection and replacement, you'll know how. Relax. It's easy and you'll get a real sense of satisfaction knowing you were able to troubleshoot a little problem like this without having to go through the hassle and expense of going to the dealership.


In general, most vehicles on the road have two types of fuses. Older cars have glass, cylinder-shaped fuses with stainless steel on the ends and glass in the middle. Most newer cars have a different style of fuse that uses a plastic housing with the fusible link encased in the housing.

If a device or system on your vehicle isn't working and you suspect a fuse might be the culprit, the first step is to look in your owner's manual. The manual will help you locate the fuse box and tell you how to access it. On older cars, the box was usually located underneath the dash to the left of the brake pedal or near the parking brake pedal. There was no cover for it, but it was still a major hassle to view because of the bizarre angle you had to place your head at to actually see it.

Where are my fuses?
Automotive fuses are usually found under the drivers side dashboard. A compartment cover may need to be removed or the fuse box may be mounted on the firewall between the engine and the dashboard out of sight but readily accessible for maintenance.

Many models of cars will split the fuse box location between the normal location near the driver and a remote location under the hood. If you have two fuse boxes then the fuses that are found under your hood will normally protect the circuits needed to run your engines electrical system and the ones found in the drivers compartment will protect circuits for your headlights, radio, blower motor and other devices.

A third place you can find automotive fuses would be inline fuses used when accessories are installed. You will commonly find an inline fuse installed on car radios. This type of fuse is barrel shaped and different then your average automotive fuse.

Finally you may have a Main Fuse which is a 1×1 inch box located near your drivers firewall fuse box that protects the electric fuel pump and a portion of your starting circuit.

These four locations are the most common places you can find fuses in your cars electrical system, however when a third party device is added a fuse may be used.

Once you've located the fuse box, you have to determine which fuse needs to be removed for inspection. Again, your owner's manual will help you do that. Say, for example, the backup lights don't work. Most owner's manual provides a numerical chart to explain which fuses correspond with which device or system.

Some cars provide a pair of tweezers to help you remove a fuse. If your car doesn't have this nifty little feature, you're not out of luck. You might be able to remove the fuse by hand, but in most cases, you'll need a small pair of needle-nose or standard pliers to get the fuse out of the box.

Once the fuse is singled out and removed, you need to determine if it's blown. This is usually quite easy. For the older glass fuses as well as the new plastic ones, if the metal link inside the fuse is separated, the fuse is toast. If not, then it's still good and can be reinstalled.

If the fuse is blown, the next step is finding a proper replacement. Some cars come with a supply of spares; otherwise, you'll need to make a quick trip to the auto parts store (or have the foresight to purchase a small assortment of fuses to keep in the car). The most critical element to replacing a fuse is using the exact same amperage rating as the blown one. If you use a fuse with different amperage rating, you risk either blowing the fuse again, or damaging the equipment the fuse is designed to protect.

The idea behind a fuse is that it's supposed to blow if there's a surge or short in the device or system's electrical wiring. For example, if it's a 10-amp fuse that needs replacing and you replace it with only a 5-amp fuse, the smaller fuse will blow much sooner than it needs to. Conversely, if you replace that 10-amp fuse with a 20-amp unit, it's possible you'll damage the part or system before the fuse has a chance to break and save the component.

So, once you determine the fuse is blown and procure a suitable replacement, it's time to reinstall the new one. This is the easiest part. With the new plastic fuses, they plug right back into the fuse box and usually fit into place with a little pressure from your fingers.  With older glass fuses, the installation process is a bit tougher, as they are installed by pressing one end at a time. We'll also note that with the glass fuses, different amperage ratings sometimes come in different lengths, so the right amperage rating is not only crucial from an electrical standpoint, but from a sizing one, too.

Following is a step-by-step guide to replacing a fuse :

You will need
• 1 set of fuses
• 1 fuse puller
• 1 pair of tweezers
1. Step 1: Secure the car

Secure the car.

Switch off the ignition. No electricity should flow during a fuse check.

Apply the parking brake....
If you have a manual transmission, shift into 1st gear; with an automatic transmission, put the gear stick into the parking position.

2. Step 2: Locate the fuse panel:

Fuse panels are usually located under a cover below the steering wheel, left of the column.
Remove the cover. It has a fuse diagram printed on it. You will see the fuses sitting in the panel.

You will immediately notice the different colours indicating different ratings.

3. If you have trouble finding the fuse box consult your car manual for details of the location.
Often the fuse panel is found under the bonnet. Remove the cover and access the fuse panel.


4. Step 3: Check the fuse diagram
Check the fuse diagram.
The fuse diagram is a simplified numerical chart that explains which fuses correspond to which device or system. The devices are represented by easy to understand symbols.
Work out which fuse needs to be removed for inspection.

5. Step 4: Remove the fuse
Remove the fuse now.
To remove the fuse that you have singled out, simply pull it from the panel. Use the plastic puller for doing this - otherwise, use your fingers or tweezers.

6. Step 5: Check the fuse
Check the fuse.
Determine if the fuse in question is blown. If the metal link inside the fuse is separated, the fuse has melted. If it looks normal it can be plugged back in, however, you may still have electrical problem. In this case, it's best to consult a mechanic.

7. Step 6: Replace the fuse
Replace the fuse.

Place a new fuse with exactly the same amperage rating in the puller.
Be sure to use the correct rating, remember to go by the colour and the number stamped on the fuse.

SAFETY WARNING !

A fuse with the wrong rating may damage the electric equipment it's designed to protect. Avoid a fire hazard and consult a mechanic if the initial problem remains after you've replaced the fuse.
o Push the new fuse firmly into its slot in the fuse box. If it is askew it will not work.
o Push it down with your fingers for a correct fit. A useful tip.
If you're left without any spare fuses you can still take a fuse from a non essential circuit. Check if your car has a working cigarette lighter and take the lighter out of its socket to remind yourself that you will have to replace the fuse later.
o Check the diagram in order to find the lighter fuse.
o Take out the fuse and put it into the required circuit slot.
Alternative devices to temporarily take a fuse from are the radio or, if temperatures allow for it, the rear window heating.

8. Step 7: Check circuit
Check the circuit.

Switch on the ignition and switch on the circuit in question.


If you cannot operate the device, and the new fuse blows immediately there is a problem that should be checked by a mechanic.
If the device works correctly after fuse replacement, you can quickly check if the main electrical functions on your car work properly.

Hope this provides you with some useful information that will help if you have occasion to use it!

11 comments:

  1. great stuff man, im gonna try this out, lights in my car dont work properly, when you open the door sometimes it lights up and other times well dont.

    ReplyDelete
  2. I never knew this! Thanks! Thought I'd stop by and show my support.

    ReplyDelete
  3. Useful tip, tahnks. Come check me out, alphabetalife.blogspot.com

    ReplyDelete
  4. Thanks for this guide! Yep, it really will help me out in the future :)

    ReplyDelete
  5. Wow, this is some useful information. Thanks!

    ReplyDelete
  6. Great info! I had a fuse blow on my A/C in the middle of summer. I was glad it was just a fuse and not something else!

    ReplyDelete
  7. THis just happend to me the other day!

    ReplyDelete
  8. This saved me so much money thank you for posting this.

    ReplyDelete
  9. Wish I would have read your blog post here a few weeks ago.. Had a blown fuse and no clue what to do. D:

    ReplyDelete
  10. I'm truly inspired by your blog! Great to read once again. Keep this up!

    - Pappa Püllï

    ReplyDelete