Fusible link keeps blowing over and over

[kdurham1982]

I just regained power to dash and ignition in my 82 c10, however now when I turn the truck over and it starts it immediately blows the fuse in my fusible link near the solenoid. The link down by the starter is fine but the other one blows every time it attempts to start. Any ideas on what the problem is?

 

[AuroraGirl]

I just regained power to dash and ignition in my 82 c10, however now when I turn the truck over and it starts it immediately blows the fuse in my fusible link near the solenoid. The link down by the starter is fine but the other one blows every time it attempts to start. Any ideas on what the problem is?

What is the fuse link for specifically? Fuse link protects the wire not the components, so an improved wire will eliminate the need for fuse link

 

[Radiohead]

Uh, I don't think that's what a fusible link is all about. It's a fuse, an extremely slow blow variety, so brief current surges can pass without tripping the fuse. If a fuse link is burning up like described, my first thought is that there is a serious fault to ground somewhere on that circuit. An "improved wire" will only encourage a fire somewhere else in the circuit, probably where the fault is. Which isn't a diagnostic method I can recommend.

 

[WP29P4A]

That is a classic symptom of a short, sounds like you have a good solid short which will make it easier to find.

 

[WP29P4A]

A fusible link is designed to melt before the wires on that circuit, so it doesn't melt the whole wiring loom. It is a sacrificial piece, meant to save the wiring and components connected to that circuit. like a sacrificial anode on a boat.

Looking at a wiring diagram to see what is connected to that fusible link will help you to know where to look for the short. If the truck worked before you worked on it, triple checking EVERYTHING you touched when you worked on it, is the first place to start. Check for pinched wires.

 

[WP29P4A]

If you hooked the battery up backwards like someone mentioned in your other thread, the alternator will most likely need to be replaced to correct the short.

 

[SirRobyn0]

I agree with what every one has said here and with @AuroraGirl A fusible link is primarily to protect wiring not to protect components, though they can, they are pretty slow to burn out. Mainly they blow when there is a bad short to ground and the primary purpose is to prevent a wiring melt down. I'd be looking for a BAD wiring rub though. Kind of had to really direct you to where that might be you need to get in there and see where that fusible link wire runs too.

 

[AuroraGirl]

Uh, I don't think that's what a fusible link is all about. It's a fuse, an extremely slow blow variety, so brief current surges can pass without tripping the fuse. If a fuse link is burning up like described, my first thought is that there is a serious fault to ground somewhere on that circuit. An "improved wire" will only encourage a fire somewhere else in the circuit, probably where the fault is. Which isn't a diagnostic method I can recommend.

a fuse also isnt for protecting the end component, although we are generally smart enouh with how we wire and install things that quick overages dont usually kill things and usually pop fuses/links/maxifuses etc

 

[R Carnella]

Disconnect the B+ wire at the alternator and try again.

 

[SquareRoot]

Put a heavy gauge jumper in place of the fuse. Start truck. Look for smoke. You found the problem. Replace or repair. Reinstall fusible link. Drink beer. Carry on.

 

[WP29P4A]

a fuse also isnt for protecting the end component, although we are generally smart enouh with how we wire and install things that quick overages dont usually kill things and usually pop fuses/links/maxifuses etc

A fuse is basically an isolation device, it separates the "problem" from the rest of the system when it blows, it's also an indicator, if it blows, you have been notified of a problem. Fuses don't care what they protect.

 

[Ricko1966]

I've got a tool for doing this but an improvised version would be wire a head light in place of your fuseable link turn your key on the light should light. Take a clampon ammeter and start tracing back the harness when you quit showing amps on your meter,you've just passed your short.
I'm pretty sure the magic box that is the heart of the one I bought is just a 2 prong flasher relay in a box with 2 wires with alligator clips on them. But I'd hate for anyone to find out it's not a flasher relay in a box. But a headlight bulb should give enough amperage draw to trace.

 

[70SBUDGET]

any chance you worked on the starter recently and one of the positive wires is grounded?

 

[BadBowtie]

 

[KnuckleBuster]

Put a heavy gauge jumper in place of the fuse. Start truck. Look for smoke. You found the problem. Replace or repair. Reinstall fusible link. Drink beer. Carry on.

Yuck.