# 30amp fuse melted - did not pop. fuse holder also slightly burned looking



## 96jimmyslt (Jan 31, 2011)

ok so I have 3 strands of 18awg for the power and ground from the battery, 3 feet to the sub amp (RF p500-2)

the fuse holder is probably 10awg and has a 30 amp fuse in it

before this, all it did was come loose a little bit

it was about 70F today and it's been really cold before this.

I'm wondering what is going on.


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## Ziggy (Nov 29, 2007)

CHINA... strikes again!


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## sbcaprice305 (Jan 17, 2012)

halarious


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## 96jimmyslt (Jan 31, 2011)




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## sbcaprice305 (Jan 17, 2012)

Even funnier. Keep em' coming.


Did you use duct tape to secure the ground to the chassis?


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## 96jimmyslt (Jan 31, 2011)

been working fine for weeks like this up until now


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## Sleeves (Oct 22, 2010)

I'm hoping (from looking at your post count) this is posted in jest.

If so: lulz.


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## Sulley (Dec 8, 2008)

Sleeves said:


> I'm hoping (from looking at your post count) this is posted in jest.
> 
> If so: lulz.


Haha I hope soo because.....


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## 96jimmyslt (Jan 31, 2011)

This is not a joke

I had a 40 amp maxi fuse on it before and tried with the 30 amp and so far so good

I figured the smaller the fuse, the more protected it would be...

Am I correct to assume that the amp could handle a spike of up to 100 amps and that a 100 amp fuse would be fine?

I have the 100amp RF fuse holder and fuse which is 8awg.


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## sbcaprice305 (Jan 17, 2012)

So you have a fosgate 100a fuse and holder with 8awg input/outputs? If so pic up some 8awg at a absolute minimum to replace the wire your using. 4awg would be ideal but you'd have to pick up a new holder as well.


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## 96jimmyslt (Jan 31, 2011)

sbcaprice305 said:


> So you have a fosgate 100a fuse and holder with 8awg input/outputs? If so pic up some 8awg at a absolute minimum to replace the wire your using . 4awg would be ideal but you'd have to pick up a new holder as well.


yea and I have enough 8awg to wire both power and ground.

like I said, I figured the smaller the fuse, the more protection I would have.

and since it didn't pop, I figured it was fine.

I have a 250amp anl fuse/fuse holder but thats clearly too big.

I don't see why I would /need/ 4 or 8awg for this application but I will use 8awg


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## Sulley (Dec 8, 2008)

96jimmyslt said:


> This is not a joke


Are you sure...?


I suggest you install a good quality 4 gauge kit before you catch your car on fire. Your fuse is also suppose to be installed a few inches away from the battery, less then 18" actually. 

Such as this one ---> Rockford Fosgate RFK4


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## 96jimmyslt (Jan 31, 2011)

I've got 4awg too

would it be ok to just cut enough wires to fit 4awg into the 8awg set screw fuse holder?

edit: it's funny because in my last car I had 4awg wired into a fused distribution block and then had 4awg going to this amp..but I had a 40 amp fuse for the sub amp and 20 amp fuse for the highs amp, and even another 25 or so amp fuse in this same fuse holder in the picture right before the highs amp


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## haromaster87 (Jan 20, 2012)

96jimmyslt said:


> I've got 4awg too
> 
> would it be ok to just cut enough wires to fit 4awg into the 8awg set screw fuse holder?
> 
> edit: it's funny because in my last car I had 4awg wired into a fused distribution block and then had 4awg going to this amp..but I had a 40 amp fuse for the sub amp and 20 amp fuse for the highs amp, and even another 25 or so amp fuse in this same fuse holder in the picture right before the highs amp


I don't want to speak for everyone else here, but I think what everyone is trying to say is that your 3 strands of 18g wire are not going to cut it. Also, I think manufacturers set values for what size fuse is supposed to be used on the amp. For starters.


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## benny (Apr 7, 2008)

Sleeves said:


> I'm hoping (from looking at your post count) this is posted in jest.
> 
> If so: lulz.


If you look at some of this guys posts, you'd almost think he was a troll. Then something like this comes up and make you realize that he's no troll, he actually really has no clue.


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## Mike_Dee (Mar 26, 2011)

See how the prong is burnt? To me it appears to have not been making good contact in the fuse holder, causing the burn marks from arching. That would cause it to melt.

Get a new fuse holder.

Also increase the size of your B+ to 4 ga.


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## Sulley (Dec 8, 2008)

96jimmyslt said:


> yea and I have enough 8awg to wire both power and ground.
> 
> like I said, I figured the smaller the fuse, the more protection I would have.
> 
> ...


The theoretical maximum current load for 3 runs of 18awg wire is about 13.5 amps

I always go by the fuse rating recommended from the manufacture and RF is saying 100a. Will your amplifier draw 100 amps of current when set up correctly? Probably not. If you have 4 gauge wire, Please use it. Under sizing a fuse by a few amps typically won't matter but it still has to be large enough to supply adequate current to the amp.

A fuse is to protect the wire as much as the electronics, I suggest you read at least the first few paragrahs of this site ---> BCAE1 - FUSES


This is page taken out of the Iasca SQI Installation Rules 2010 Handbook. For 8 gauge wire the MAXIMUM fuse size recommend for 15 feet is 50 AMPS, The link I posted above also states the same.


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## Sleeves (Oct 22, 2010)

I've used that exact model of amp to power my front components before. For the best performance in your situation, I would use *at least* true 8AWG wire for power and ground (you do not find this in the $20 amp kits from Wal-Mart or your local pawn shop) and a 40 or 50 amp fuse at the battery. I feel that RF has enough protection circuitry in the amp that a fuse near it is fairly pointless and will only net you some unnecessary voltage drop. The fusing at the battery, on the other hand, is critical in protecting your car from fire in case the wire gets grounded out somehow. 

That small wire you are currently using is acting as a choke for the current going to your amp. Sure it "works", but it is creating extra heat from trying to move more current than the wiring is rated for and the poor connections in the fuse holder are resistance points wasting current as heat. Pulling more than the rated current coupled with a low quality fuse holder is why it melted. You should definitely be a lot happier with the safety and performance of your equipment if you can find the time to upgrade the wire and connections.


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## hilander999 (Jul 6, 2011)

*=*


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## chad (Jun 30, 2005)

It was not over-current, it would have blown. see where it was arcing? THAT connection could not take the pressure.


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## kyheng (Jan 31, 2007)

That wire for your amp is good for 10-15A if it is true AWG... Since you are using the amp for sub, it will draw more certain time..
Always use bigger cable if possible and use smaller fuse for your amp, like your amp require 50A, a 30-40A will be good enough....


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## 96jimmyslt (Jan 31, 2011)

Ok i have monster 8awg 4 inches long from the battery to the fuse holder, with a 50amp fuse, then about 3 feet of monster 8awg to the amp.

I have about the same length of rockford 8awg to the negative battery terminal.

The rubber around the wire is very thin.

I am glad everyone got a kick out of this...

Thank you all for the help.

Also, would running the ground wire to the chassis be better?

What about 4awg just for the ground?

How about 4awg to the fuse holder and cutting some strands off to fit into the 8awg terminals, or getting a 8-4awg adapter?


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## jdsoldger (Feb 14, 2012)

As a side note to all this, the first fuse it to protect the wiring, not the amp (and like someone else said should be as close to the battery as possible). This fuse should never be more than the rated currant the wire wire can take, which depends not only on the gauge but the length. The fuses on the amp are for protecting the amp.


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## cruzinbill (Jul 15, 2011)

96jimmyslt said:


> Ok i have monster 8awg 4 inches long from the battery to the fuse holder, with a 50amp fuse, then about 3 feet of monster 8awg to the amp.
> 
> I have about the same length of rockford 8awg to the negative battery terminal.
> 
> ...


Where do you have the ground ran to now? Also, for the love of god dont go shaving the wire down to fit, if the max size that will fit in the amp is 8 then run an 8g ground... if 4 is the max run a 4. Trimming down strands to fit is as bad as twisting a bunch of smaller ones together to equal a bigger one.


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## Malazan (Apr 13, 2012)

hilander999 said:


> *=*


:laugh:


I peed a little


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## gtsdohcvvtli (Aug 17, 2011)

Wow


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## Lars Ulriched (Oct 31, 2009)

Subscribed.....this thread is confusing....


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## jdsoldger (Feb 14, 2012)

cruzinbill said:


> Where do you have the ground ran to now? Also, for the love of god dont go shaving the wire down to fit, if the max size that will fit in the amp is 8 then run an 8g ground... if 4 is the max run a 4. Trimming down strands to fit is as bad as twisting a bunch of smaller ones together to equal a bigger one.


Actually, twisting a bunch together is perfectly fine. Though you would need 10 or 11 18 gauge wires to be the same as 8 awg and 26 of them to be the same as 4.


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## IBcivic (Jan 6, 2009)

jdsoldger said:


> Actually, twisting a bunch together is perfectly fine. Though you would need 10 or 11 18 gauge wires to be the same as 8 awg and 26 of them to be the same as 4.


Only if they are individually fused


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## minbari (Mar 3, 2011)

as mentioned by others, the wire is not large enough for the current draw.

and replace the fuse holder. those $1 holders do not have enough surface contact on the fuse to do anything but heat it.


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## MarkZ (Dec 5, 2005)

Where on earth are you guys coming up with the idea that the WIRE was at fault???? You're ignoring the fact that the problem occurred at the fuse and fuse holder. The wiring had nothing to do with anything.

While I agree that it wouldn't hurt to upgrade the wiring from 3x18ga (for a number of reasons, including the fact that I don't think it's a good idea to run multiple wires to a single terminal, because you fail short rather than fail open )... the best way to solve the problem is to make sure the connections are secure and the terminals are robust. Those crappy blade fuse holders _suck_.


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## chad (Jun 30, 2005)

MarkZ said:


> Where on earth are you guys coming up with the idea that the WIRE was at fault???? You're ignoring the fact that the problem occurred at the fuse and fuse holder. The wiring had nothing to do with anything.


Jesus man, have you not figured it out... IT'S ALWAYS the wire... lights dimming, go bigger on wire to the amps so they can pull more current. 

I think the battery terminal melted the fuse


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## Sleeves (Oct 22, 2010)

chad said:


> Jesus man, have you not figured it out... IT'S ALWAYS the wire... lights dimming, go bigger on wire to the amps so they can pull more current.
> 
> I think the battery terminal melted the fuse


I understand you're trying to use sarcasm here, but I actually have upgraded wire and fixed poor connections from bad installations with the end results being better performance and *less* pulsing of the headlights with system use. Yes, it's counter-intuitive but it can happen.


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## Ziggy (Nov 29, 2007)

So what actually happened to the fuse?... Spark kept arcing over when it tried to pop -and it re-soldered itself? :surprised:

Just trying to keep it educational.


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## Oliver (Jun 25, 2007)

chad said:


> It was not over-current, it would have blown. see where it was arcing? THAT connection could not take the pressure.


I agree Chad !

simply a bad or loose connection 

The guy does not appear to be over-driving his equipment - * BRAVO !*


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## chad (Jun 30, 2005)

Ziggy said:


> So what actually happened to the fuse?... Spark kept arcing over when it tried to pop -and it re-soldered itself? :surprised:
> 
> Just trying to keep it educational.



It never tried to pop, the female spade terminal with a small amount of contact area was less capable of handling the current than the fuse element.

It's just that simple


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## IBcivic (Jan 6, 2009)

An electrical circuit WILL always fail at it's weakest point

Usually, you would want this point to be the fuse's element.


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## MarkZ (Dec 5, 2005)

IBcivic said:


> An electrical circuit WILL always fail at it's weakest point


This.

Which is why I've always felt it was silly that people would be worried about a (relatively) thick piece of wire heating up and melting the insulation off, when you've got a tiny fuse element sitting there all by its lonesome.




> Usually, you would want this point to be the fuse's element.


Yup, or at least a transistor that won't take out half a circuit if it goes. Like in a crowbar.


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## cruzinbill (Jul 15, 2011)

MarkZ said:


> Where on earth are you guys coming up with the idea that the WIRE was at fault???? You're ignoring the fact that the problem occurred at the fuse and fuse holder. The wiring had nothing to do with anything.
> 
> While I agree that it wouldn't hurt to upgrade the wiring from 3x18ga (for a number of reasons, including the fact that I don't think it's a good idea to run multiple wires to a single terminal, because you fail short rather than fail open )... the best way to solve the problem is to make sure the connections are secure and the terminals are robust. Those crappy blade fuse holders _suck_.


Just so dumbfounded that this is a real install I think I completely over looked the itty bitty fuse and holder when i saw the twisted and gnarled together wire ran.... I think he would have been better off getting a 20$ walmart kit.


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