April 30th, 2004 : About Fusible Links
After fully educating myself about fusible links and how they work, I decided -- hands down -- I'd rather have a fusible link than a circuit breaker or in-line fuse for certain things (like my electric fan) any day.
"What if a fusible link goes while I'm on the road?" was my first question ... but I didn't realize how dependable fusible links were when I asked that question! First of all, you can easily keep a spare handy. But, more importantly, fusible links never fry unless there's a very serious problem that needs your immediate attention (like a major power wire grounding against metal!); a problem that a circuit breaker or in-line fuse could mask well enough to have you finding your car in flames. Fusible links are the safest way to protect your electrical system and keep your vehicle from an electrical fire.
An in-line fuse on a 30-amp electric fan circuit (as I discovered) won't last very long. When that fan kicks in, it's more likely to pull 60 amps (initially) than 30 and after a dozen times or so that in-line fuse will give up it's ghost and burn out -- it's a gradual breakdown that occurs.
Just like an in-line fuse, a 30-amp circuit breaker is also subject to wearing out and eventually frying ... it just takes longer.
A fusible link will never wear out. It will only burn out protecting your vehicle from bursting into flames due to a serious short that needs your immediate attention -- nothing else is gonna do that for you. You can see many fusible links in older cars, still doing their job after 20 years or more.
1 - Rule of thumb: 4 gauges smaller = the right fusible link. For an 8-gauge wire, you'll want a 12-gauge fusible link; for a 10-gauge wire, you'll want a 14-gauge fusible link; for a 12-gauge wire, you'll want a 16-gauge fusible link, etc.
2 - You don't want to use regular wire ... fusible links are different and have a non-flamable insulation. You can buy fusible links here:
3 - Never use fusible links in the interior section of a vehicle! If they ever do fry, they spark like crazy ... keep them out of the dash areas and keep them away from gas lines or anything ignitable.
P.S. -- You may be interested in checking these electrical projects out:
Mad Electrical Improvements -- [Click Here]
Wiring An Electric Fan With Two Relays -- [Click Here]
Headlight Relays -- [Click Here]
Wiring Dome Light via Door Switches -- [Click Here]
Understanding Relays -- [Click Here]