Wire from Alternator to Battery
Thread Starter
Pro
Joined: Nov 2007
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From: Northern Florida
Wire from Alternator to Battery
Questions please :
1. I have a 100 amp TuffStuff Alternator on my 1970 BB ; does the Alternator put out the same amps as the Car is using at any given time ? Or more ? How much more ?
2. I replaced the shabby looking #10 wire with a #6 . The plastic wire covering is pretty thick but id assume it should be run in a cover of some kind ; Wire loom ????
3. Would it be wise to add a fusible link to this wire ? WHere should it be put , and, what type is recommended ?
Any tips and suggestions ? TY, Dave
1. I have a 100 amp TuffStuff Alternator on my 1970 BB ; does the Alternator put out the same amps as the Car is using at any given time ? Or more ? How much more ?
2. I replaced the shabby looking #10 wire with a #6 . The plastic wire covering is pretty thick but id assume it should be run in a cover of some kind ; Wire loom ????
3. Would it be wise to add a fusible link to this wire ? WHere should it be put , and, what type is recommended ?
Any tips and suggestions ? TY, Dave
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
A #6 awg braided wire would be best. Normally, the car wouldn't 'ask' for all hundred amps from the alternator at once. But, if the battery is run down for some reason, and you jumper the car to get it going, it will ask for everything the alternator can send it.
Melting Slicks
Joined: Aug 2004
Posts: 2,907
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From: Oakbank Manitoba
You will have a hard time finding a fusible link to protect a #6 ga wire. A 10 ga fusible link (the required size) will need to be special ordered. Most newer cars alternator charge wires are protected with a blade style fuse. Look up "mega fuse". That's what I use on my 1980 Corvette and Superlite Coupe.
Last edited by KENS80V; Mar 1, 2014 at 10:58 PM.
Race Director
Joined: Apr 2009
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From: Charlotte NC
I would not worry about using a fusible link or a fuse. There are NOT fuses or fusible links on or in-line of a positive battery cable....right?
I have been doing some serious custom wiring on a 1974...and I also changed the alternator wire to a much larger wire like you did. But what I did was custom make a junction block...due to so many added electrical components are being installed....it was needed....along with the factory wiring that went to the junction block.
On these wires that come off that junction block terminals...is where the wire had fusible links installed. Much like how GM placed a fusible link at your battery terminal on your starter solenoid...so the wiring that goes to your car is protected. Depending on year model...OBVIOUSLY.
DUB
I have been doing some serious custom wiring on a 1974...and I also changed the alternator wire to a much larger wire like you did. But what I did was custom make a junction block...due to so many added electrical components are being installed....it was needed....along with the factory wiring that went to the junction block.
On these wires that come off that junction block terminals...is where the wire had fusible links installed. Much like how GM placed a fusible link at your battery terminal on your starter solenoid...so the wiring that goes to your car is protected. Depending on year model...OBVIOUSLY.
DUB
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Joined: Nov 2007
Posts: 710
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From: Northern Florida
I would not worry about using a fusible link or a fuse. There are NOT fuses or fusible links on or in-line of a positive battery cable....right?
I have been doing some serious custom wiring on a 1974...and I also changed the alternator wire to a much larger wire like you did. But what I did was custom make a junction block...due to so many added electrical components are being installed....it was needed....along with the factory wiring that went to the junction block.
On these wires that come off that junction block terminals...is where the wire had fusible links installed. Much like how GM placed a fusible link at your battery terminal on your starter solenoid...so the wiring that goes to your car is protected. Depending on year model...OBVIOUSLY.
DUB
I have been doing some serious custom wiring on a 1974...and I also changed the alternator wire to a much larger wire like you did. But what I did was custom make a junction block...due to so many added electrical components are being installed....it was needed....along with the factory wiring that went to the junction block.
On these wires that come off that junction block terminals...is where the wire had fusible links installed. Much like how GM placed a fusible link at your battery terminal on your starter solenoid...so the wiring that goes to your car is protected. Depending on year model...OBVIOUSLY.
DUB
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
If you want to build a fusible link to put into that line, just stick a short run of #8 wire in the circuit. But, you must also put that wire inside a non-flammable jacket (heat-shrink tubing???) and put some JB Weld epoxy [stick-type] putty around the soldered junctions with the #6 wire. In essence, that is how GM made their fusible links: the next size smaller wire inside a non-flammable jacket and non-flammable casings on the junction points.
When the fusible link fails, the smaller wire takes the hit; but it is jacketed so that the melting wire won't catch the insulation [or terminals] on fire, either.
Unless that alternator really needs to crank out max amps, you'll never hear from that fusible link in the system. But, put it somewhere accessible and not next to any fuel-related stuff.
P.S. You might also think about your ammeter, as it doesn't read that high. I don't believe that the elevated signal level (millivolt signal from 'shunt' wire...not really 'high current' meter) will do any harm to the meter. But, a high charge rate could drive the needle to the end of the scale. You wouldn't notice anything during normal operation, though.
When the fusible link fails, the smaller wire takes the hit; but it is jacketed so that the melting wire won't catch the insulation [or terminals] on fire, either.
Unless that alternator really needs to crank out max amps, you'll never hear from that fusible link in the system. But, put it somewhere accessible and not next to any fuel-related stuff.
P.S. You might also think about your ammeter, as it doesn't read that high. I don't believe that the elevated signal level (millivolt signal from 'shunt' wire...not really 'high current' meter) will do any harm to the meter. But, a high charge rate could drive the needle to the end of the scale. You wouldn't notice anything during normal operation, though.
Last edited by 7T1vette; Mar 1, 2014 at 06:30 PM.
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From: Fernandina Beach FL
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What about a gas line? - Doesn't the rubber crack from heat and age-so you replace it....Right?
Questions please :
1. I have a 100 amp TuffStuff Alternator on my 1970 BB ; does the Alternator put out the same amps as the Car is using at any given time ? Or more ? How much more ?
It only puts out what is needed to keep the system voltage above 13.7 volts -HOWEVER- it has the ability to put out more current (than the stock one) at idle- usually when you need it.
2. I replaced the shabby looking #10 wire with a #6 . The plastic wire covering is pretty thick but id assume it should be run in a cover of some kind ; Wire loom ????
Just as long as it not flopping around- that plastic split loom really offer no extra protection,
3. Would it be wise to add a fusible link to this wire ? WHere should it be put , and, what type is recommended ?
My thoughts- NO....
Any tips and suggestions ? TY, Dave
1. I have a 100 amp TuffStuff Alternator on my 1970 BB ; does the Alternator put out the same amps as the Car is using at any given time ? Or more ? How much more ?
It only puts out what is needed to keep the system voltage above 13.7 volts -HOWEVER- it has the ability to put out more current (than the stock one) at idle- usually when you need it.
2. I replaced the shabby looking #10 wire with a #6 . The plastic wire covering is pretty thick but id assume it should be run in a cover of some kind ; Wire loom ????
Just as long as it not flopping around- that plastic split loom really offer no extra protection,
3. Would it be wise to add a fusible link to this wire ? WHere should it be put , and, what type is recommended ?
My thoughts- NO....
Any tips and suggestions ? TY, Dave
I'm running a rather large gauge wire since i have a lot of stuff to power-
Race Director
Joined: Apr 2007
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From: South Western Ontario
The alternator output current will be more then the current the car is using every time you first start the engine. This current is re-charging the battery. Once past that, the current used should equal the current produced. However, if you demand more current then the alternator can produce you'll run off the battery until either the current draw is reduced or the alternator rpm is increased so it can produce enough current. At that time, the alternator output will be higher then the car demand to re-charge the battery.
You can most certainly use a fusible link. The fusible link is selected as 2 gauge sizes smaller then the wire being protected. So, use a 10 gauge fusible link for 6 gauge wire. Use a piece about 7" or 8" long. Make a soldered or good quality crimped connection and seal it with double wall heat shrink.
You can most certainly use a fusible link. The fusible link is selected as 2 gauge sizes smaller then the wire being protected. So, use a 10 gauge fusible link for 6 gauge wire. Use a piece about 7" or 8" long. Make a soldered or good quality crimped connection and seal it with double wall heat shrink.
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From: North of Toronto - Ontario
You should be able to buy 10g fusible link at your local NAPA. I bought some small spools of various sizes but if I remember correctly they also listed pieces (9" or 10" lengths, might have been a couple in the package)
M
M
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Pro
Joined: Nov 2007
Posts: 710
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From: Northern Florida
You will have a hard time finding a fusible link to protect a #6 ga wire. A 10 ga fusible link (the required size) will need to be special ordered. Most newer cars alternator charge wires are protected with a blade style fuse. Look up "mega fuse". That's what I use on my 1980 Corvette and Superlite Coupe.
I guess regardless of the MegaFuse rating, on a direct short of the new wire I ran, the fuse is going to blow regardless (?) .
Melting Slicks
Joined: Aug 2004
Posts: 2,907
Likes: 229
From: Oakbank Manitoba
The fuse should be matched to the size of the charge wire. What you are trying to prevent is the wire from overheating and possibly catching on fire.
150 amp fuse would be close to the current carrying capacity of a #6 ga wire.
I use a 4ga wire and 175amp mega fuse.
Don't forget to purchase the matching fuse holder from them as well.
150 amp fuse would be close to the current carrying capacity of a #6 ga wire.
I use a 4ga wire and 175amp mega fuse.
Don't forget to purchase the matching fuse holder from them as well.
Last edited by KENS80V; Mar 2, 2014 at 12:57 PM.
Drifting
Joined: May 2005
Posts: 1,968
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From: East TN
I swapped the original for heavier gauge wire. I used a breaker instead of the fusible link. I installed positive and negative terminals on the firewall, then feeds the alt. and other accessories from there.
Race Director
Joined: Mar 2006
Posts: 14,112
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From: Florida
You can use several types of fuses available such as the newer cars do or you can use more than one fusible link in parallel to achieve the same effect. Manual reset breakers are nice too. They just need to be slow blow. My Ford truck has two fusible links in parallel from the factory for the alternator.
It's always a good idea to protect wires.
It's always a good idea to protect wires.