blowing fuses?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=52138
Printed Date: May 03, 2024 at 12:35 PM

Topic: blowing fuses?

Posted By: wrathchild281
Subject: blowing fuses?
Date Posted: March 18, 2005 at 5:41 PM

hey you guys i keep constantly blowing my fuses. At first i was using 60 amp fuses and now im using 80 amp fuses but they blow in like a day. A guy at a local shop said that would go away if i start using 100 amp fuses which i would need a bigger piece or whatever to fit them. Do you guys think this would fix the problem and what cuases this to happen? oh ya and have a jbl 600.1 at 1 ohm pushin 2 8's. Thanks

Replies:

Posted By: spl-Hz
Date Posted: March 18, 2005 at 6:25 PM

What size power wire are you running?

Posted By: DYohn
Date Posted: March 18, 2005 at 7:11 PM

What's drawing all the current? Your amplifier can only draw about 60 amps as a BP600.1 is fused at 60 amps.

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Posted By: AJRXtreme
Date Posted: March 18, 2005 at 8:39 PM

i hooked up his system and the only thing drawing current is the jbl 600.1. he also has factory infinity speakers being powered by a factory amp. but thats all thats drawing current. pretty wierd

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03 F150 on 24's
HU:Pioneer DVD5700
Frt:MC57
Subs:(12)S12L7
Amps:(3)KX2500.1's, MC-2004

Posted By: AJRXtreme
Date Posted: March 18, 2005 at 8:41 PM

I have a feeling since those subs are wired at 1 ohm the subs are wanting more current than the amp can provide which means the battery is trying to supply the amp with too much current and the fuse blows. Thats what happend to my system a while back when i wired my 12's at 1 ohm.

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03 F150 on 24's
HU:Pioneer DVD5700
Frt:MC57
Subs:(12)S12L7
Amps:(3)KX2500.1's, MC-2004

Posted By: DYohn
Date Posted: March 18, 2005 at 11:18 PM

Two things. First, the amp can only supply the current the fuses allow it to draw. It will blow the fuses on the amp if the continuous current exceeds 60 amps (I believe that amp has two 30-amp fuses.) Second, the amp fuses are standard slo-blo fuses, which means PEAKS can easily exceed the 60 amps since the amp can handle it, just not 60 amps sustained.

So, I bet you are blowing your main fuses (assuming there is no wiring fault like a short to ground or a bad capacitor or a high-resistance connection) because the fuses at your battery are FAST-blow type. Fuses for wiring are generally fast-blow since they are designed to protect the wire (and your car) from faults like short to ground. It is possible that the average current being used by the amp is less than 60 amps but the peaks are exceeding the 80-amp fast blow rating and this is blowing your fuse.

What gage wire are you using? Choose the fuse size based on the wire's capacity, not the amp's.

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Posted By: wrathchild281
Date Posted: March 18, 2005 at 11:57 PM

i am using 4 gauge wire. so what do size fuse do you recommend i use?

Posted By: DYohn
Date Posted: March 19, 2005 at 9:29 AM

4-gage can be safely fused up to 150 amps. I'd use the largest fuse you can afford up to that rating.

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