# Fuse on power wire keeps blowing..help



## riored4v (Jan 21, 2012)

Buddy of mine bought my old sub off and we installed it yesterday. He was previously using an Infinity Perfect sub and he bought my Dayton HO DVC sub. The sub is a DVC4ohm and we had it wired for 2ohm. The amp is a Alpine PDX 600.1 so it looks like its stable at 2ohms. 

After we swapped the subs, we turned it up and the amp cut out for a bit. Turned the car back on it and it was fine. As the volume was turned up again, it cut out and it turns out the power wire fuse blew. From what we could tell, the fuse in the power wire was pretty small so he mentioned he purchased a fuse that would equal up to the fuses in the amp (80a). Today he mentioned that the bigger fuse blew again.

Really not sure what would be causing it to keep blowing. None of the settings were changed from when he was running the Infinity sub. Any ideas?


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

If you blew a fuse on the power wire, that was larger than the fuses in the amp and the amp is fine, fuses are fine, I'd say you've got a short on the line somewhere..

Or, if you are using glass AGU fuses, you are possibly melting the solder out of the fuse (pretty common problem for AGU fuses)


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## riored4v (Jan 21, 2012)

Aaron'z 2.5RS/WRX said:


> If you blew a fuse on the power wire, that was larger than the fuses in the amp and the amp is fine, fuses are fine, I'd say you've got a short on the line somewhere..
> 
> Or, if you are using glass AGU fuses, you are possibly melting fuses (pretty common problem for AGU fuses)


At first, the fuse on the power wire was pretty small. I think only 40a. I can't recall the exact size he went with (i'll try to find out), but I did mention to atleast go 80a to match up to the fuses on the amp.

All we literally did was the pull the old sub out and put the new one in

And yea, the fuses are an old RF holder with AGU fuses.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Get rid of the fuse holder (for something better, MAXI, MIDI or ANL) and I bet the problem follows it...


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## Problemhouston (Apr 2, 2009)

Check both of the subs VC's to make sure one isn't blown. I had this happen to me when I bough a used sub off craigs list. We installed it and it would play for a minute or two then the fuse would blow. Checked the VCs and sure enough one was bad so when I had it wired in paralell the load was too much for the amp and it would just blow the fuse.


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## minbari (Mar 3, 2011)

start with the simple stuff. check gains, check your wiring on the sub, make sure it is not touching anywhere. just replacing bigger and bigger fuses will only destroy the amplifier eventually.


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## Complacent_One (Jul 2, 2009)

Since you mentioned that it was cutting out with the car off...it would also be a good idea to make sure the battery is fully charged. With a low battery you will pull more current to make up for the lack of voltage.


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## riored4v (Jan 21, 2012)

minbari said:


> start with the simple stuff. check gains, check your wiring on the sub, make sure it is not touching anywhere. just replacing bigger and bigger fuses will only destroy the amplifier eventually.


If I recall, the gain on the amp was turned all the way down. Which I thought was extremely weird for it be playing as loud as it was before the fuse blew.


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## riored4v (Jan 21, 2012)

Problemhouston said:


> Check both of the subs VC's to make sure one isn't blown. I had this happen to me when I bough a used sub off craigs list. We installed it and it would play for a minute or two then the fuse would blow. Checked the VCs and sure enough one was bad so when I had it wired in paralell the load was too much for the amp and it would just blow the fuse.


How do I do that?

Only thing I can think of is that maybe it blew on his car? I had it wired to my audioque amp running 2ohm and I was able to turn it up as loud as I wanted and it never popped any fuses.

The sub was probably a month old:blush:


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## riored4v (Jan 21, 2012)

Aaron'z 2.5RS/WRX said:


> Get rid of the fuse holder (for something better, MAXI, MIDI or ANL) and I bet the problem follows it...


Would an 80a fuse be suffecient for that amp?


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## Complacent_One (Jul 2, 2009)

riored4v said:


> Would an 80a fuse be suffecient for that amp?


I typically add up the fuse ratings of the amplifiers and add 20 percent...not a hard fast rule, but the fuse at the the battery is there to protect the wire...that is it. The amplifiers onboard fuses are for protecting their internals...


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## riored4v (Jan 21, 2012)

Complacent_One said:


> I typically add up the fuse ratings of the amplifiers and add 20 percent...not a hard fast rule, but the fuse at the the battery is there to protect the wire...that is it. The amplifiers onboard fuses are for protecting their internals...


Ok, i was a little off on what I told him then. He had 4x20a fuses and I think he went with a 80a fuse on the power wire.


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## Complacent_One (Jul 2, 2009)

80 should be fine...again, not a hard fast rule. You must take into consideration that not everything is perfect scenario in a car...so there are some inherent efficiency issues that can show up......as stated earlier, if your battery is spent, then you may show 13.6-14.4VDC at the battery with the car idling without a load, but you start cracking open the volume and load it down and that voltage may drop to 11 plus or minus. That can cause an increase in current demand, and in turn do crazy things.

Do some good troubleshooting...like doublecheck all your power connections..ie..battery, grounds, etc. If those all look good, then I would recommend sticking a trickle charge on it overnight, then revisiting the issue the next day. Make sure you start your testing with the vehicle running.


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## riored4v (Jan 21, 2012)

Complacent_One said:


> 80 should be fine...again, not a hard fast rule. You must take into consideration that not everything is perfect scenario in a car...so there are some inherent efficiency issues that can show up......as stated earlier, if your battery is spent, then you may show 13.6-14.4VDC at the battery with the car idling without a load, but you start cracking open the volume and load it down and that voltage may drop to 11 plus or minus. That can cause an increase in current demand, and in turn do crazy things.
> 
> Do some good troubleshooting...like doublecheck all your power connections..ie..battery, grounds, etc. If those all look good, then I would recommend sticking a trickle charge on it overnight, then revisiting the issue the next day. Make sure you start your testing with the vehicle running.


hadn't thought of the battery being bad. When we did all the tests the car was running though. I'll mention the battey info to him.


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## Complacent_One (Jul 2, 2009)

Not necessarily bad...just needs a full charge.


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## nutxo (Feb 24, 2008)

Complacent_One said:


> I typically add up the fuse ratings of the amplifiers and add 20 percent...not a hard fast rule, but the fuse at the the battery is there to protect the wire...that is it. The amplifiers onboard fuses are for protecting their internals...


I'd argue the fuse holder at the battery is to protect the car and its wiring.

Last summer I heard some yelling outside and poked my head out to see what was going on. Directly in front of my house was a huge Chevy caprice on giant rims painted bright green. Some guy screaming at his woman that the car was overheating and for her to pop the hood. So I headed out and grabbed my hose.

As I got closer to the car I smelled smoke, not antifreeze, I ran up and took a look. I saw the 1/0 against a tube that came off the exhaust manifold arcing and a lot of wiring actually smoking there were random flames all over the place.. I told the guy to disconnect the battery and ran back in the house to get a fire extinguisher.

I got back out and the guy was screaming for a wrench  I grabbed some pliers . Put out the fire and disconnected the guys stuff. The first thing the guy says after all of this is " can I drive it? " I told him maybe but I wouldn't. All the wiring for the fans was toast and got knows what else was burnt. He left the stereo power wire off ,reconnected the battery ,got in and started it.

He got back out of the car and thanked me and said " If theres ever anything I can do for you just ask" So I said he could refill my extinguisher. He asked how much it costs and I told him I thought it would be like 20 bucks. He kinda of looked at me and says " Nah, I dotn think so" got in his car and drove off.

I should have let it burn and posted video on youtube


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## minbari (Mar 3, 2011)

nutxo said:


> *I'd argue the fuse holder at the battery is to protect the car and its wiring.*
> 
> Last summer I heard some yelling outside and poked my head out to see what was going on. Directly in front of my house was a huge Chevy caprice on giant rims painted bright green. Some guy screaming at his woman that the car was overheating and for her to pop the hood. So I headed out and grabbed my hose.
> 
> ...


that is what he said. if you look he said "but the fuse at the the battery is there to protect the wire...that is it."


classic! lol. I guess by "just ask" didnt mean he would actually do it, lol. douch bag, lol. you saved his multi-thousand dollar dork-mobile but he couldnt give you $20? I would have let it burn too.


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## Complacent_One (Jul 2, 2009)

nutxo said:


> I'd argue the fuse holder at the battery is to protect the car and its wiring.
> 
> Last summer I heard some yelling outside and poked my head out to see what was going on. Directly in front of my house was a huge Chevy caprice on giant rims painted bright green. Some guy screaming at his woman that the car was overheating and for her to pop the hood. So I headed out and grabbed my hose.
> 
> ...


Well it was a good thing you were there...huh...

Not sure what the argument would be....I plainly stated it is to protect the wire....you just went from the action of to a consequence of not "protecting the power wire"....

Just like a seatbelt is for protecting a vehicles occupant...but I suppose the argument could be made that it is for protecting the windshield or the steering wheel...or perhaps the lamp post or the trunk of the vehicle directly in front....


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## nutxo (Feb 24, 2008)

Complacent_One said:


> Well it was a good thing you were there...huh...
> 
> Not sure what the argument would be....I plainly stated it is to protect the wire....you just went from the action of to a consequence of not "protecting the power wire"....
> 
> Just like a seatbelt is for protecting a vehicles occupant...but I suppose the argument could be made that it is for protecting the windshield or the steering wheel...or perhaps the lamp post or the trunk of the vehicle directly in front....


LOL. It just gave me a chance to tell a great story


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

nutxo said:


> *I'd argue the fuse holder at the battery is to protect the car and its wiring.*


 
I'm not sure if I would argue that point here, cause you'd be wrong... 



My guess is dude's power line wasn't fused, or wasn't fused close enough to the battery... 

The lead coming off the battery is supposed to be no longer than 18"... and the shorter the better, for the very reason that something to potentially come in contact with the wire in 18"


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