Fusible link Question

[Aussiedeza]

Hello, my alternator died on me a while back and i finally have the time and money to buy a new one.

After lots of looking and head scratching i purchased this guy https://www.summitracing.com/int/parts/pwm-7509/overview/ a 95 amp power master alt. So i figured while i wait for this new alternator to arrive i better do some wire upgrades to handle the higher Amps and disconnect the amp gauge out of the equation so my question according to a bunch of sources i need to run a 4 gauge wire from my new alt to the starter relay and a 4 gauge wire requires a 8 gauge fusible link am i wrong coming to this conclusion as i have been looking everywhere and I cant seem to find fusible link wire larger than 12 gauge..

Cheers guys would really appreciate being pointed in the right direction on this one.

[burdar]

You don't need a 4 gauge wire for the bypass.  This link shows a 10 gauge bypass wire with a 14 gauge fusible link. It wouldn't hurt to run an 8 gauge bypass and a 12 gauge link.
http://www.madelectrical.com/electricaltech/amp-gauges2.shtml

You're higher amperage alternator won't put out any more amps then the stock alternator unless you've added extra electrical loads to the vehicle.  If you've added extra loads, that's when the wiring upgrades are needed.

[Aussiedeza]

Hi Burdar, thanks for your input mate the mad electrical link is what I have been using for reference and i should of mentioned that I have installed a few extras that would draw extra electrical load which is why i opted for a higher amp alternator this time as it was really struggling before for instance power windows would go up and down super slow and turn off the radio when pressed.

I figured the best plan would be to get the wire recommended for 95 amps and lots of sites show graphs like this one suggesting 4 gauge, if you think i can get away with using 8 gauge that would make my life easier sourcing a fusible link.

[lulurocks]

for the alternator:

Under 10' you need #6   with a #12 link

Over you Need #4 as per manufactures specs. with a #12 link

 
http://www.powermastermotorsports.com/charge_wires_a.html



for the bypass you need 8 with a #16 link

anytime you tap power you need a fuse or a link to protect the wire from an over-current fault or fault to ground. 

[burdar]

The MAD article says to remove the factory charge wire from the alternator and to hook it up to the starter relay with a fusible link.  Personally, I would put a fusible link on the end of the factory charge wire and leave it hooked up to the alternator.(less wiring to do)  Then run your 8 gauge bypass wire.  This way, you are charging the battery with the bypass wire AND the original charge wire. 

It's also been debated if you even need a fusible link on the bypass wire if you are running it directly to the battery or relay.

[burdar]

According to that chart, 85-105 amps can use an 8 gauge wire if it's under 7' in length.

[lulurocks]

 

According to that chart, 85-105 amps can use an 8 gauge wire if it's under 7' in length.

all depending on his specific routing .... 

[Aussiedeza]

Ok i just bought some 6 awg wire and some 10 awg fusible links, kinda wana try and neaten up the bay a bit so that should give me some flexibility with routing. thanks for the info guys. 

[lulurocks]

Ok i just bought some 6 awg wire and some 10 awg fusible links, kinda wana try and neaten up the bay a bit so that should give me some flexibility with routing. thanks for the info guys. 

that will work for the alternator  ,  but the #10 link is too big for the bypass if you chose to do it , you are interfacing existing wiring at that point and your link needs to mirror the size of the link of what your essentially re-feeding .  again protecting the existing  harness wiring  ..

[Cudaragtop]

Ampacity has a lot to do with the type of wire you use... Some far exceed the NEC [National Electrical Code]
Best to stay away from crap wire from Home Depot or Lowes...

Power cables we use in Telecom DC power systems.
http://www.cobrawire.com/x-flex/x-flex150.php

[jhaag]

Also might want to look at using relays for your power windows and other add ons. 

[dodj]

While bigger wire is always better for current flow, those charts are for sustained current. Your alternator is usually putting out about 5- 15 amps. More at night. You're never pumping out 80-100 amps other than extremely briefly. If you are, you will be on fire. 

[HP_Cuda]

Can you imagine the sound system that would draw 100A, your car will melt down to a cinder but hell it will sound *****in!!!