Upgrading 65A Alternator to a 130A

ferrall

Petty Officer 3rd Class
Joined
Jun 21, 2010
Messages
96
Well, that was it. Put a jumper in between S and Exc and now she puts out 14.8 volts. My old alt must have been internally connected. As far as upgrading wiring do I need to basically put 4 AWG from the alt to the circuit breaker and then to the relay. How do I get a terminal small enough to fit on the alternator's tiny terminals but large enough to handle the 4 gauge wire?
 

alldodge

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Staff member
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Mar 8, 2009
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40,705
You could keep it like it is and wait and see if the breaker will blow. If the breaker blows then you need to bypass it and use larger wire. While the ALT can put out more amps, it will only do this if the battery needs it. So if the breaker never blows your OK. If you do need to replace it you can find a larger lug, trim it down and drill another hole to fit. Use the starter connection before the other if the wire size is not larger enough 11vp wiring.jpg
 
Last edited:

jeffnick

Senior Chief Petty Officer
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May 24, 2004
Messages
695
A larger wire will take most of the current only because it will have less voltage drop for a given current. The ratio of current by the two wires is a ratio of the resistance of each wire.

And as the current/temp increases on the lower resistance wire, wouldn't the other wire start taking the load?
 

ferrall

Petty Officer 3rd Class
Joined
Jun 21, 2010
Messages
96
Thanks so much guys. You've helped me so much. Thanks for the wiring diagram too! Ok, so now that this alt thing is done I have another electrical issue. Should I start a new thread?
 
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