# Amp install with no in-line power fuse?



## mzmtg (Dec 8, 2009)

I'm planning to mount my amplifier in the corner of my trunk, right over the battery (E36 BMW). 

Since the power connections will be inches from the battery, do I really need to try and fit an inline fuse in there somewhere?


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## savagebee (Sep 12, 2006)

does the amp have its own onboard protection fuses?


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## mzmtg (Dec 8, 2009)

savagebee said:


> does the amp have its own onboard protection fuses?


Yes, two 25-amp blade fuses. It's an old MTX Thunder 4244.


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## Brian10962001 (Jul 11, 2009)

No, it will be fine. Think about it, you have around 18in of wire pre fuse block in your average install, you're just terminating at the amp instead of into the fuse block.


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## mzmtg (Dec 8, 2009)

That's what I figured.

I thought I'd ask a dumb question just to make sure I wasn't overlooking anything.


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## blazeplacid (May 19, 2008)

i say fuse it

the fuses on the amp are for the amp

you are not protecting the wire


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## mzmtg (Dec 8, 2009)

blazeplacid said:


> i say fuse it
> 
> the fuses on the amp are for the amp
> 
> you are not protecting the wire



The wire is 12" long.


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## Lanson (Jan 9, 2007)

If it is under 12" long, I see no reason to fuse it. That's the standard fusing distance for a normal run anyway. If the amp has no internal fuses, well then your answer is clear.


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## Brian10962001 (Jul 11, 2009)

For what it's worth, I have burnt up an amplifier (Rockford Fosgate) despite inline fusing, the fuse didn't even blow and yes it was the proper size. It was actually 10 amps smaller than what the amp called for. I really think inline fusing is for the power wire more so than the amp. It's just one of those safety things you don't want to overlook.


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## sqshoestring (Jun 19, 2007)

Its for the wire. I'd say fuse it on the battery. If you can't and there is _no way _that wire can short on anything, then you could get away without it if the amp has fuses....but it should be fused on battery. Issue is about any wire kit you buy the fuse is a foot from the battery anyway. Really a fuse block on the post is best, but even the factory does not do that.


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## TeamLorett (Dec 25, 2009)

You would normaly fuse the amp withing the first foot so it would be pointless to fuse it if it is only a foot long since the amp is fused. The only purpose in that fuse is to stop the wire from shorting on the chassis. Just make sure there is no chance of wire shaffing or throw some wire loom over it.


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## nsaspook (May 19, 2009)

mzmtg said:


> I'm planning to mount my amplifier in the corner of my trunk, right over the battery (E36 BMW).
> 
> Since the power connections will be inches from the battery, do I really need to try and fit an inline fuse in there somewhere?


Because of my pal "Murphy" I would fuse it anyway.


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## Austin (Mar 12, 2009)

I vote for some split loom over the wire and no fuse. You will be fine and won't cause any fires.


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## synth808 (Feb 20, 2009)

you will have to be diligent as far as ever disconnecting your battery before servicing the amp. It would suck to disconnect the wire and have it accidentally ground out without being fused.


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## Capt Steve (Dec 18, 2009)

mzmtg said:


> I'm planning to mount my amplifier in the corner of my trunk, right over the battery (E36 BMW).


I don't know if you mean in the same compartment. If you are, I would be more concerned with the battery out-gassing and what impact the gas will have on the amp. I don't think hydrogen sulfide gas is good for the amp internals. 

I also think that the gas is explosive and I don't know if having a amp that close to the battery is safe. 

Maybe someone who knows better can chime in here.


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## TeamLorett (Dec 25, 2009)

Capt Steve said:


> I don't know if you mean in the same compartment. If you are, I would be more concerned with the battery out-gassing and what impact the gas will have on the amp. I don't think hydrogen sulfide gas is good for the amp internals.
> 
> I also think that the gas is explosive and I don't know if having a amp that close to the battery is safe.
> 
> Maybe someone who knows better can chime in here.


Yeah Steve, good points but the BMW usually mount the batt in the rear as that is the stock location. I am guessing you thought he moved it in perhaps the passenger compartment. Many cars have moved the batt to the rear seat with a cover or to the trunk to assist in weight distribution or just lack of space. Good points though!


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## TeamLorett (Dec 25, 2009)

nsaspook said:


> Because of my pal "Murphy" I would fuse it anyway.


Murphy visits us every Saturday (which is my Friday) at my job.


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## mzmtg (Dec 8, 2009)

TeamLorett said:


> Yeah Steve, good points but the BMW usually mount the batt in the rear as that is the stock location. I am guessing you thought he moved it in perhaps the passenger compartment. Many cars have moved the batt to the rear seat with a cover or to the trunk to assist in weight distribution or just lack of space. Good points though!


The battery is factory-mounted in the trunk and has special fittings to vent gasses to the outside.


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