jbl gto7001
alpine type r 15'

bought a 1000watt amp kit which included 4 gauge wires and a 100A fuse for $100
then bought 4 gauge wires for the big3 upgrade $20

and just bought 150A fuse with a 'CMWFH Mini Wafer Fuse Holder' that look like this:

for $30 both

i already spent $150 on wires and fuses. fml.
i hope that the 150A fuse is good for the alt-batt connection (with a 4ga wire)

ps. the dealer at the store said that i dont even need a fuse for my alt-batt connection, i told him that you guys recommended getting a fuse and he said thats fine.. but he said that my system will be going through a tiny metal fuse instead of flowing free in a 4ga wire.
i told him ill get it just in case and since i trust you guys more.

is there a factory fuse currently in my 2010 civic lx? the alt-batt wire is tiny and im not sure if there is a fuse anywhere

i got my dad explaining to me some things and here is what he told me,
W = U*I
700watt = 12I
I = 58.3A (+20% just in case) = 70A
since stores dont sell 60A, 61A, 62A... they sell 60A, 80A, 100A (approximately) so from what i understand i got a bit more than needed but unless i crank the volume all the way up and leave it there for an hour, shouldnt be a problem.
as for the alternator to battery, my dad said that he saw that the factory fuse is 100A (but he's not too sure), and if i put a 4ga wire with 150A fuse in parallel to that factor wire (with the factory fuse), ill pretty much cancel out the factory wire and the current will go through the new wire. as he said, if the can is designed for 100A fuse, and i put 150A fuse, and suddenly there is a jump in voltage lets say 110A goes through, then the alternator will get f-ed. and from what i understood is that 100A would melt down and stop the current flow if those 110A suddenly come by..
hope that makes sense :S

so pretty much what he is saying is that he doesnt see a reason for doing this upgrade and thinks that it even puts the car in risk if i put 150A fuse..
he is an electrical engineer so i obviously trust him, but on the other hand, so many people do it and you guys tell me to do so what should i do.. could someone explain to me the deal with this whole thing?

 

I think a fact you should tell him is this very simple one:

if you get in a head on collision your factory use will blow but your pinched batt to alt wire which could touch the chassis could change an airbag blowing accident into a car fire. I would think that if you tried to match the output rating of your alt and fuse the same or slightly higher you should be fine. If you haven't blown your factory fuse due to current demands, then you are probably fine unless the system controlling your Alts output fails.

 

hmm.. big words there lol, but mainly im talking about powering up my bass system and reducing the light dimming problem. i know ill need a group34 battery but thats later on. first i want the big3 done and ive done only 2/3 of the big3 upgrade (the battery(-) to ground and batt(-) to engine block) both without a fuse obviously. my last wire is the alt to battery(+) and im just in doubt what fuse size to use.. people say 150A, my dad says 100A but he also says its a risk so not to do the upgrade at all :S

btw. its a 2010 honda civic lx

 

Dude, you really should have followed through with me and done as I recommended I hate to say. That said, the + line battery to alternator must be fused, just like the factory lines are (they use a fuseable link). Put the lower fuse in there, if it blows due to too much draw, then put the larger fuse in.

 

One fuse will be completely pointless. The purpose of a fuse is to protect the wire from melting due to excess amperage, but once you get into 0/1 gauge then you don't really have to worry about your system doing that. However, shorting a wire from say an accident is a great way to cause a fire because the amperage is going to skyrocket real fast. If you do decide to fuse the amp - alternator power wire, you should get a fuse as close to the battery and alternator as possible. One fuse is going to restrict flow and not protect the wire from shorting out.

I'm not a fan of fusing, especially once you run tons of wire just to have it bottleneck through a tiny fuse, but at the end of the day the value of staying safe is too great. Do it properly.

 

what do you mean? ive done 2/3 wire upgrade for the big3 (both grounds) and the last one left is the alt-batt wire.
i bought the stuff locally 5min away from my house.. so there was no point ordering it from you
i got a fuse as everyone is recommending, but my question is, how big should it be? right now i have in my hands 150A fuse with a fuse holder ready to get installed.. but is it good for my car? and is it what i need?

why would i wait for the factory fuse to blow out if i want to upgrade the wires (add 4 gauge wire to the factory one). when i add the wire ill need to fuse it other wise im canceling out the factory fuse and putting my car at risk

 

4 gauge wire in chunks was $1.00 per foot. We have an entire bin full of it for this exact reason. It is why I told you to use string to measure the wire run by the foot and not just one long run of say 15 feet at $3.50 - $6.00 ft (depending on type of wire). Shipping, it could have been dropped off to you at no charge as I had numerous people pass throught the lower mainland. But what is done is done. If it works for you that is all that matters. Lets solve your fuse issue.

If you have a 150amp fuse and holder in your hand for the new 4 gauge line from the battery to the alternator, by all means use it. There is only going to be a couple of reasons for it to blow.

1) your draw of current has completely depleted your battery and it is drawing way more than the fuse is rated for. If this happens you have huge a$$ problems that would crop up as symptoms way before that fuse ever blew.

2) you have Ford planted on your forehead after running into the back of a pickup while texting while driving thus dead shorting the now pinched wire against the engine.

3) the battery has dead shorted for some reason.

4) the alternator has dead shorted.

5) the wire was improperly ran and not secured. It made contact with the exhaust manifold and melted into a mess before dead shorting and blowing all sorts of fuses and releasing smoke from under the hood.

I was not speaking about waiting for the factory fuse to blow out. I read your post as though you had two new fuses for the new 4 guage run and which one should you use, the 100amp or the 150amp. Start small, if it blows then look for signs of problems and replace with the larger one.

 

the 100A fuse is currently being used for the power wire from battery(+) to my amp
the 150A fuse that i just bought today is my question.. as i said, putting it there isnt the problem, im just worried that this will cause problems because the car wasnt designed to have 150A fuse over there.. (my dad said he saw a fuse from the factory connection that said 100A but he wasnt sure about it). so if i add 150A fuse to the already existing 100A fuse, im now pretty much have 250A fuse kinda deal (from the formula Itotal = I1+I2+....)
so if for example, 120A is drown, it will damage the alternator because it was designed for max of 100A.. i hope i make sense

 

Put the 150 amp fuse on the positive wire from your alternator to your + battery... your alternator may be only good for 100-120 amps, however if that wire was to go to ground you could send in upwards of 450+ amps through the wire... by having even the 150amp fuse inline with your alt/batt wire at least it will blow the fuse and not fuse the wire to any piece of bare metal that it now has available... a current path with no fuse can equal fire...

 

and read everything at bcae1.com

this is science