Printer Friendly Forum Posts - melting my fuse block

I am running a MA Audio SY5011DX at 1ohm to 2 12" Fosgate hx2's with 4 gauge wire. My problem is that the battery side of the fuse block is getting so hot that its melting the plastic base and corroding. would higher gauge help this problem. the fuse is 150a.

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

How many watts are pushing?
How long is the 4 gauge wire?

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S type R.

I'm running it at 1ohm which its rated at 1000w for 1ohm. it roughly 17" long. I've been to a couple of stereo shops that sell amp kits for 1000 watts amps and they all had 4 gauge in them. I checked on Crutchfield on their "cable gauge selection chart" and for a 16-19" run and a 120A pull it suggests 4 gauge. My amp has 4 30a fuses on the outside so I assumed that it would pull 120A.

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

Um, I guess I didn't read the right way to figure out the draw of my amp. they say to double the rms wattage and then divide by 13.8 and that is the amp draw. In that case I'm drawing 144a which the chart recommends 2 gauge. Does all this sound right?

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

Might be engine heat affecting that portion of the wire. I don't suppose it has a loom installed over it? You might just replace that short section from the battery to the fuse holder, and cover the part of the wire that is in the engine bay with a loom. You wouldn't have more than 120 amps flowing through the wire without blowing fuses in the amp.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

This is in a Landrover Discovery and the fuseblock is in a side compartment of the battery box which is shielded from most of the engine heat. Like I said its only the side of the fuseblock that's closest to the battery. the other side isn't corroded, discolored, or melted.

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

There's no resistance at the fuse. The electric flows the same at the beginning of the wire, through the fuse, and at the end of the wire. It doesn't make sense to me. But it never hurts a thing to upgrade wiring.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

it could also just be a cheap fuse block.... good quality fuse holders of that amperage will be made of a bakelite composite and you can hold a propane torch to them without them melting... sounds like yours is made of plastic which will indeed melt under the current requirements you mentioned.....

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Kevin Gerry
Certified Electronics Technician
MECP First Class Installer

Owner/Installer
Classic Car Audio
since 1979

don't listen to anybody except for the last guy who replyed "kgerry" he knows what he is talking about. first i would upgrade to two gauge, then i would invest in a good quality fuse holder. If you think about it you have thick four gauge wire throughout the vehicle right? but the flow isn't the same, look how small the fuse connection is on your fuse, the amount of current allowed to pass through the four gauge wire is only the amount allowed by the fuse. voltage is like pressure, and a fuse in kinda like a resistor, its a give and take relationship when one is higher than the other. That might be the reason for the meltdown. good luck

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gangstaville installer

Ok I was wrong about which side was melting. It's the amp side of the fuseblock. I asked 3 different shops today about this problem. #1 said that I could upgrade to 2 or 1gauge wire, increase rating, or add another cap. #2 said to upgrade wire and get new fuseblock. #3 said it could be a bad connection on the screws that connect the fuse to the block and causing it to spark and/or heat up. He also said to solder the wire and ring terminal connection together to get better connection. since i bought the block from shop #3 the gave me a better fuse block which is the waterproof type that the case screws on from the side just like the stinger SAWFH04. I just have to change out the damaged one and give it back to them so they can warranty it out. The block I have now isn't cheap, it's just the metal is getting so hot and the plastic it's attached to is melting.

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

aye there's the rub..... the metal shouldnt be attached to plastic...it should be attached to a bakelite compound base which isnt effected by heat transferance.... any primary fuse block that is rated over 100 amps of current and is made of plastic is a cheap fuse block... sorry to say

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Kevin Gerry
Certified Electronics Technician
MECP First Class Installer

Owner/Installer
Classic Car Audio
since 1979

I just got done checking and the only one like you describe would be made by Stinger(maybe one by Phoenix Gold). Monstercable, streetwires, Knukonceptz, tsunami and RF are all cheap? None of those companines say anythnig about having high-temp cases. The new one that I recieved today is Hooker. Anyone heard of this brand?

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

I can't believe that a shop told you tou needed a cap!!

What a sad world we live in......

The problem is indeed caused by a bad connection. You have mentioned corrosion. Yes it is a cheap fuse holder, but the fuse will blow if the current is to high...and there really is no reason for it to melt if the wiring is done correctly.

I would still get a better fuse holder and upgrade to 2 gauge...kgerry is right, cheap junk doesn't belong in your car.

Why not get a breaker?

Since you have installed the new fuse holder has it started melting? If so I would look into a circuit breaker.

gtown installer wrote:

...look how small the fuse connection is on your fuse, the amount of current allowed to pass through the four gauge wire is only the amount allowed by the fuse. voltage is like pressure, and a fuse in kinda like a resistor...

gklown installer, have you gone back to the books and done your homework yet? You hafta know the purpose of a fuse...

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

'voltage is like pressure'

yea, I think I know what book he's been reading too, MECP bronz level study guide?

Another of my favorite lines from that book is "electron theory states that current flows from the negative to the positive, in this book we will stick with conventional theory to keep it simple (positive to negative) "

Let's undo this gross misuse of terminology right now.....voltage is potential.

There can be 100,000 volts at that fuse holder and the fuse will not blow unless it's current rating is exceeded.

It is a resistor in a sense, it does have some resistance, when it gets hot enough, it is supposed to open. Since it is a slow blow, it won't open right away, but it still adds resistance.

The fuse itself cannot generate enough heat to melt plastic, at that point it will be ready to blow and the heat is in the filament not likely to be in the ends and wiring, the connectors and 4 awg wire act as a big heat sink if this is the case. If there is a crusty stale connection with lots of current going through it, there can easilly be enough heat build-up to do some damage!

If corroding is a problem for you, you might want to smear some 'dielectric silicone compound' on the connections of your new fuse holder to prevent this. Any electronics or auto parts store has it.

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You'd better get me out of this lord... or else you'll have me to deal with. -- Hunter S. Thompson "F.A.L.I.L.V."

ok, thanks for all the replies. I haven't been on the pc in a couple of days. I haven't changed the fuse block yet since I really don't want something to happen to this on too. I have taken the old one out and gave it back to the shop.
You'll be proud to hear that I used the "search" function on this site to find the best deal on some 1/0 gauge wire. It should be here on tuesday which is why I'm waiting til then to put the new fuseblock in. Knukonceptz has the wire for $2.25 a foot. Not a bad deal. The new block that was given to me doesn't say anything about being a "bakelite" type base so I'll be watching this one very closely.
Any suggestions on whether I should stay with a 150A fuse or go bigger?

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

As long as you're running the same equipment use the same fuse. Since your demand is not greater than 150 amps.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

now that you say that, the same shop that told me that another cap could be a solution also told be that if I double the fuse rating amount on the amp thats how much the amp is pulling at full load. that would indicate that it possible for it to be pulling 240a at full volume. I told him how Crutchfield says to measure the pull to which he replied that he deals with real world current pull which is like he said double what the amp rating is.

as far as the circuit breaker goes I read on www.bcae1.com that these aren't as fast and/or reliable as fuses as far as protecting electronic equipment like amps and radios.

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

Did that guy take you for an idiot, or is he a shining example of one? An amp will not operate if its fuses are blown, and that's what happens if it pulls more current than the total sum of its fuses. And for the circuit breaker, BCAE was talking about protecting equipment, not wires, so it is perfectly acceptable to protect the power wire with a breaker.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

well this sucks since i've been trusting this same guy for about 13 years and he's never steered me wrong. He also said he wasn't impressed with my new choice for my sub amp which is a JBL 2200.1. I mean if Biggs and Eldridge use them they should be pretty good.

I must have just misunderstood the bcae site when i read it. Should I find a circuit breaker with the same fuse rating as my current fuse?

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

Then I would have to say he was referring to the comparison of output against something other than the amp's fuse rating. I guess. But what does he advise over the JBL? The breaker just has to be of a higher rating than the sum of the amp fuses. Here is one that is rated close.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

[QUOTE=flynntech]

Let's undo this gross misuse of terminology right now.....voltage is potential.

Close but I think you mean voltage is the differenece of potential.

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if i just cut the red wire....no the green wire ,, oh damnit i'm so screwed..

The important thing to know about a fuse is that it is a safety device. It is designed to burn out in a controlled and safe manner when the amperage flow through it exceeds its rating. It is not a control valve, or a floodgate, that controls the flow of amperes. Its relative size has nothing to do with anything, meaning one cannot judge a fuse by comparing it to the thickness of the adjoining wiring. That also means that the amperage flow is not bottled up in the portion of wire before the fuse and only allowed to trickle through the fuse at the fuse's amp rating. That is a decidedly totally wrong impression of what a fuse does.
The amplifier puts the demand on the power source (alternator and battery). The amplifier is the control device. The alt and battery are its servants and the power wire and in-line fuse are the conduit that carries the amperage. There is resistance in every component of an electrical system, the fuse being one, the wire also being one. That doesn't mean that the fuse and wire should be called "resistors". Because they provide some resistance doesn't make them resistors. If that were the case everything we deal with in a system would be called a resistor.

This is a response, not to the original post, but to a respondent earlier on who implied that I didn't know what I was talking about and then went on to describe an erroneous idea of what a fuse does. Since both fusing and grounding share the status of being the most critical elements in an car audio system, I wanted to clear that up.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

RAMBOY: "Close but I think you mean voltage is the differenece of potential."

Yup, that's what I meant. ;)

Wow......double the fuse values...double the bass?

how much crack is this guy smoking?

A breaker will open quick enough if the positive wire is pinched and shorted to the body of the car, which is all it needs to do. It won't matter if it's 150A or 500A. The moment that wire shorts to ground, that breaker going to flip. Since such a short would demand full current from the battery/alt the voltage at the amp would be 0, not likely to get damaged.

JBL makes good amps. You should go back and talk to this guy everyday, just to post what he said here. This nonsense is getting better and better!

I'm not sure I could come up with a different question everyday just to go in there. I will say that this is a first for him though. My main pet peeve is when a sales guy trashes everything except for what he sells. This guy just said he wasn't "impressed" with the JBL and tried to sell me on a Treo 1500.1. He told me that it would put out 3250wts at .25ohm's. I told him "who the drives around running .25ohm's?" At 1ohm its rated at 1500wts, but it costs over a grand. Umm, nope, not sold on it. He said the the technology that Crown/JBL is pushing is old stuff, not new. I believe that they have never said it was new, just new to the car audio scene.

I'll get the new wire in tuesday and most likely get in installed by wednesday.

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

I'll look for a bigger circuit breaker tomorrow. Thanks for all of the advice guys.

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Pioneer DEH-P980BT, Zapco DCREF1000.4,Pioneer TS-C520PRS, Adire Extremis, MTX TA91002, TC Sounds TC-3000 15"

yup...... one qaurter ohm impedence....very usefull.

Being that JBL/crown is a division of the Harmon Cardon company or something like that, I'm sure thier products are perfectly fine for audio use.

Regardless of whether technology is new or old....an amp is an amp. I have an old school Kenwood home reciever with dual power suplies and FET amps (field effect transistors). It must be from the late sixties, it's rated at 90 watts total, but it absolutely cranks. Match it to the right speakers and you have more sound than you could ever possibly need in one house....unless ofcourse, there is a party of some sort.

3200 watts??? what is the need for that much power? Sure, 3.2kW, what about the electrical system?