Melted Fuse Holder in Engine Compartment

[aggieEB]

Here's the situation: I've had one 4 guage wire running from battery, through fuse holder to a power block in the back of my ex that runs power to two amps. One amp is a rockford punch 250 w that powers a 10 inch sub. The other is a kenwood 100 w that powers the two front component set speakers. Last week the speakers in front started coming in and out and then died about three/four days ago...no sound and no power to the speaker amp (the sub amp sill had power and played the sub at a very quiet level).

So in troubleshooting it, I noticed that the fuse holder was completely melted...looks like it had been thrown into the fire. I've had this setup for about 2 years without any problems before so I don't think it was too close to any hotspots in the engine compartment. What would have caused something like this and if it was power consumption, why wouldn't the fuse break? I think the fuse was rated at 60 amps but I put it in years ago so I don't really remember exactly. Any thoughts on what I should do differently when I replace the fuse holder? In the meantime, I disconnected the wire from the batter, cut out the fuse holder, and have the rest of the wire running through the firewall capped off.

 

[BBQ_HotDogs]

You could have gotten ahold of a bad fuse holder. I would buy anothre fuse holder and fuse, install it, then turn everything on. Get an amp meter and check to see what amps you are pulling through that wire. After that, if it is OK, then don't worry about it. You may have other problems too, but you need to check the obvious first.

 

[97FordExpXLT]

Upgrade your fuse to a larger rating

 

[draft]

Upgrade your fuse to a larger rating

Why? I run around 1k off of a 60A on 4gauge wiring. I haven't had a problem since. And he's only pulling maybe 300W (doesn't even need 4ga, could use 8ga).

Just replace the fuse holder and fuse, you'll be fine.

 

[Cartman]

DO NOT PUT IN A LARGER FUSE,

The fuse should have blown if the current flowing generating enough heat to melt the fuse holder. With this happening after 2 years of use I don't think it is a faulty fuse holder either.

BBQ_hotdogs is right, get a new fuse holder and check everthing with a meter. Was the fuse holder melted on one end only - I'm thinking that if the wire wasn't attached properly (slipping out over time) that could have caused only one small area to have to conduct all the power which could cause too much heat without the current draw being enough to blow the fuse.

 

[aggieEB]

By upgrading the fuse, that will only make things worse right? In this case, I would have much rather had the fuse break instead of the entire fuse holder melting.

To answer the previous question, it isn't just one end that is melted...it's the whole durn thing man. Really really strange as like I said, everything's been peachy for two years. I'd like to blame it on the hot weather but this happened during the winter...it just doesn't mesh with the small amount I know about electricity and car stereos. If this was a "too much power" problem, it should have blown the fuse...but it just melted the whole thing...

Who knows. Thanks for the info guys. I've already got some scosche fuses and holders on the way from crutchfield...gonna give this another shot.

 

[draft]

Won't make it worse, just there's no point at all with the power you're pulling. Glad you got some replacements on the way, should be a nice 5-10 minute job to fix.

Should be good to go.

 

[BBQ_HotDogs]

I don't know right off hand, but you have 4g wire. You need to find out the max amps that the 4g wire will carry without burning. What ever that rating is what you need to carry for a fuse. Do not put a fuse in that is bigger than the rating of the wire. That is how fires get started. If 4g wire is rated at 45amps max load, then do not put any fuse bigger than 45amp rated. Make sense?

 

[typhoon43]

4 Gauge will hold A LOT more than what this guy is pushing. Check for shorts in the 4 gauge all the way back. Does it tun under your truck by any chance? Make sure nothing cut into it that would cause a short.

 

[heyok]

aggieEB, I work on a lot of old broadcast transmitters and when we find problems with melted parts it is often caused by connectors not being torqued down enough. The problem might take a long time to show up, but what happens is that as a connection heats and cools and therefore expands and contracts, it starts to work a bit loose. A loose connection will have a slightly higher resistance in that part of the circuit and will start to heat up. I suspect that this happened to the connection at your fuse. It might be caused by a screw terminal that could have been done up a little tighter or perhaps a crimp connection that didn't hold properly. Keep this in mind when you replace your fuse and maybe go over your other connections and make sure that they are tight.

I hope things work out for you!

Al

 

[draft]

I don't know right off hand, but you have 4g wire. You need to find out the max amps that the 4g wire will carry without burning. What ever that rating is what you need to carry for a fuse. Do not put a fuse in that is bigger than the rating of the wire. That is how fires get started. If 4g wire is rated at 45amps max load, then do not put any fuse bigger than 45amp rated. Make sense?

Not really. The most universal setups are usually 8g/30A, 4g/60A and so on. Remember, the fuse is just there to assure anything shorts and doesn't cause anymore harm. Having a larger fuse is hardly harmful in any case. 4g could easily handle 1500-2000 watts in my eyes, give or take some.

heyok's overview seems really logical to me.

 

[mhn3773]

having a fuse that is larger then what a 4ga wire can handel totaly and completely defeats the purpose of putting a fuse in there anways...the fuse is NO to save the batt NOT to save the amp but to save the wire from burning down the car..if the fuse allows more amps then the wire can handel the wire will melt the insulation and cause a fire

i did HVAC work more then a year..i know alot about fuses and circuit brakers and how to properly fuse things...houses burn down becuase people buy whatever braker they want or they put in a bigger one because theres keeps blowing..that WILL let the wire try to carry to many amps and..well explode

sry to go all ****..but an idiot that worked with me prety much set a house on fire not adhering to the fusing rules

also u said it will handel 1500-200k watts..but thats not really whats at call for his situation...its more like insulation shreds wire becomes new ground for the alt/batt wire fries

or say u are un hooking the amp w.o disconecting the neg terminal on the batt ( done it more then once) and u accidenty ground it on the body of the car..sizzle

 

[BBQ_HotDogs]

Not really. The most universal setups are usually 8g/30A, 4g/60A and so on. Remember, the fuse is just there to assure anything shorts and doesn't cause anymore harm. Having a larger fuse is hardly harmful in any case. 4g could easily handle 1500-2000 watts in my eyes, give or take some.

heyok's overview seems really logical to me.

draft, but you are right and wrong in this case. The fuse is there to prevent the wire from burning period. Not to prevent the amps or anything else from burning. If an amp shorts or catches fire, the fuse is to pop to stop power from going to that amp. You CANNOT put a larger fuse in line than what the wire is rated to carry, period. This is what cause fires. Just sit back and think about it for a minute, if you are going to put larger fuses in line that is rated more than what the wire can carry, then why bother at all? Why not put tin foil in there instead? And it is not watts that makes a wire rated here, it is amperage. Number of amps drawn by ALL the equipment hooked up to that power sourse, not watts. Also I checked the UL rating for 4ga wire and it is 60amps. Meaning you cannot go with a 65amp fuse.

 

[mhn3773]

well by watts bbq he is meaning the output of the amp a general guage..u know like over yadda yadda generally fuse yadda u know what i mean

 

[aggieEB]

Heyok, you make a lot of sense. I think that is probably what happened in this case because it fits exactly what you describe. Thanks for the advice.

 

[heyok]

Heyok, you make a lot of sense. I think that is probably what happened in this case because it fits exactly what you describe. Thanks for the advice.

My pleasure aggieEB!

Cheers,
Al

 

[94ZebraRanger]

It sounds like it was pulling too much current thiought the fuse and over heated it. 300 amps though 8guage BS. I was using 8guage with 2 amps one 25wx2 and one 12.5wx2 high current. the high current amp kept shuting down untill I changed to 4 guage. Plus I had the amp personally ran though tech by the factory rep, no problem found. Why do you think I am running 1/0 for 2 amps with a total of 160 amp draw.

Tim