Topic: Alternator cables

[road2damascus]

Felipe, so you are saying you have 2 cables mounted to the insulated bracket on the alternator -- 1 that is the original going directly to the fuse box and out of that to the battery and 1 (say 4 gauge) that runs straight to the battery and has a fuse  added?   

This is what I do.

[chrisfranklin]

What size fuse are we talking about for a 220amp alternator with the 4 gauge wire going direct to the battery (in addition to the wiring through the PD box)?

[jfrabat]

Felipe, so you are saying you have 2 cables mounted to the insulated bracket on the alternator -- 1 that is the original going directly to the fuse box and out of that to the battery and 1 (say 4 gauge) that runs straight to the battery and has a fuse  added?   

Yes, I have two cables; the stocker and an extra one running from the alternator to the battery.

What sized fuse do you have on the wire running from your 164 alternator to the battery? 

But I have no fuse in the new line; it just goes straight to the battery.

[road2damascus]

Same

Yes, I have two cables; the stocker and an extra one running from the alternator to the battery.

But I have no fuse in the new line; it just goes straight to the battery.

Same for me

[chrisfranklin]

Hmmm...that's interesting.  Sounds like I could probably get away with installing the alternator with the 4 gauge wiring for the time being and then maybe look in to installing an inline fuse or circuit breaker later. 

[Jeffy]

Felipe, so you are saying you have 2 cables mounted to the insulated bracket on the alternator -- 1 that is the original going directly to the fuse box and out of that to the battery and 1 (say 4 gauge) that runs straight to the battery and has a fuse  added?  

If that's working, that's probably the way I'd go.  Don't have the greatest logistics setup for messing with wiring through the PD box (finding myself doing all this on the street, at night, with my place and extra tools miles away)  

What sized fuse do you have on the wire running from your 164 alternator to the battery?  

You don't have a choice.  The alternator is 220A.  Your stock wiring can handle 100A (Max) and the 4 gauge can handle 135A (Max).  That leaves you a 15A overhead.

You would want to run a 135A fuse or circuit breaker on there.  I'd go with a CB.

[sharpxmen]

You don't have a choice.  The alternator is 220A.  Your stock wiring can handle 100A (Max) and the 4 gauge can handle 135A (Max).  That leaves you a 15A overhead.

You would want to run a 135A fuse or circuit breaker on there.  I'd go with a CB.

there's no point in running a 135 Amp fuse on the second circuit, should be 100A just like the other one.

[Jeffy]

there's no point in running a 135 Amp fuse on the second circuit, should be 100A just like the other one.

He's going to be 20A short if the alternator goes 100% output.

[sharpxmen]

He's going to be 20A short if the alternator goes 100% output.

if you have a 25A fuse in parallel with a 50A fuse (for the sake of argument and as an example) the most you can run thru that circuit is 50Amps and not 75, once you go over 50Amp, so let's say 51Amps, 1/2 the circuit would be overloaded at 25.5A, the 25A fuse will blow, the other 1/2 will be at 51A and will also fail.

in his case, at 201 amps same thing will happen, having a 135Amp fuse doesn't mean it will carry more current, there is no current limiter on the other side of the circuit and will fail once it's over it's rating.

so it's not the sum of the rated amps on the fuses but 2x max supported on the lower rated 1/2 of the circuit.

That's what i was trying to say.

[Jeffy]

if you have a 25A fuse in parallel with a 50A fuse (for the sake of argument and as an example) the most you can run thru that circuit is 50Amps and not 75, once you go over 50Amp, so let's say 51Amps, 1/2 the circuit would be overloaded at 25.5A, the 25A fuse will blow, the other 1/2 will be at 51A and will also fail.

in his case, at 201 amps same thing will happen, having a 135Amp fuse doesn't mean it will carry more current, there is no current limiter on the other side of the circuit and will fail once it's over it's rating.

so it's not the sum of the rated amps on the fuses but 2x max supported on the lower rated 1/2 of the circuit.

That's what i was trying to say.

Yeah, once the first circuit gets overloaded it will cascade into the second and trip it no matter what. Although if he does blow the 100A stock circuit and he could limp by on the 135A without cutting himself short so to speak as long as he's not pulling 100%.  I doubt he's be putting the alternator under 100% unless he's got an onboard welder, winching and has all the lights on at the same time.  Should also probably have dual batteries for that setup anyway.  Hopefully not a stock battery in any case.

[chrisfranklin]

   (I need to work on my electrical understanding/know-how...)  

The oem "circuit" with the 10 gauge (?) wiring, 100amp fuse, and path from the alternator through the PD Box and to the battery: is this wiring something I can disconnect entirely (at least where it attaches to the alternator)?  

If so, and since this new alternator is a 220amp unit, could I then just one-wire-it from the new alternator to the positive terminal on the battery using the 4 gauge wiring I have?  

This would involve approximately 3-4 feet of 4 gauge wire which, I guess, would accommodate 175-200 amps according to this chart at Powermaster http://www.powermastermotorsports.com/charge_wires.html.  However, if I was doing it this way, would it be advisable to install a higher amp fuse or circuit breaker -- not 100amp, 135amp, but say 200amp?

[chrisfranklin]

The oem "circuit" with the 10 gauge (?) wiring, 100amp fuse, and path from the alternator through the PD Box and to the battery: is this wiring something I can disconnect entirely (at least where it attaches to the alternator)?  

If so, and since this new alternator is a 220amp unit, could I then just one-wire-it from the new alternator to the positive terminal on the battery using the 4 gauge wiring I have?  

This would involve approximately 3-4 feet of 4 gauge wire which, I guess, would accommodate 175-200 amps according to this chart at Powermaster http://www.powermastermotorsports.com/charge_wires.html.  However, if I was doing it this way, would it be advisable to install a higher amp fuse or circuit breaker -- not 100amp, 135amp, but say 200amp?

So what do you guys think about the above?        




                            
            

[Jeffy]

  (I need to work on my electrical understanding/know-how...) 

The oem "circuit" with the 10 gauge (?) wiring, 100amp fuse, and path from the alternator through the PD Box and to the battery: is this wiring something I can disconnect entirely (at least where it attaches to the alternator)?   

If so, and since this new alternator is a 220amp unit, could I then just one-wire-it from the new alternator to the positive terminal on the battery using the 4 gauge wiring I have? 

This would involve approximately 3-4 feet of 4 gauge wire which, I guess, would accommodate 175-200 amps according to this chart at Powermaster http://www.powermastermotorsports.com/charge_wires.html.  However, if I was doing it this way, would it be advisable to install a higher amp fuse or circuit breaker -- not 100amp, 135amp, but say 200amp?

You've over thinking it. Keep the stock setup.  Use the 4 gauge.  Use a circuit breaker on it like a Bussman.  You could use a 100A but I'd still use a 135A as they cost the same anyway.  If you wanted to get rid of the stock setup, it would be a lot more work and you'd probably want to use 2, 1 or even 0 gauge.  Problem with 1 or 0 is that the wire is thick and getting an eye connector that small might be difficult.