Alternator Amperage
#2
TECH Senior Member
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Question.. what other electrical devices are you running ?.. Fans, radio, lights, AC, Heater Fan, etc ?
If you looking to just run then engine. 40+ amps would be enough. Add up what you have, Electrical Fans, Fuel Pump and anything else you have.
Most GM cars and trucks now a days have 100 - 140 amp alternator to handle the load of all of the electrical devices and load, which includes the engine, lights, seat warmers, AC, USB ports, etc..
If you looking to just run then engine. 40+ amps would be enough. Add up what you have, Electrical Fans, Fuel Pump and anything else you have.
Most GM cars and trucks now a days have 100 - 140 amp alternator to handle the load of all of the electrical devices and load, which includes the engine, lights, seat warmers, AC, USB ports, etc..
#4
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The EFI stuff draws a surprising amount of current. Just look at the fuse sizes for the computer, heated oxygen sensors (if you have them) and fuel pump. For a ball park number just add up whatever fuses you have feeding the engine equipment.
Having said that I would think any alternator you put on there will be more than large enough. Even the old carb'd motors had alternators that would produce 45+ amps.
Having said that I would think any alternator you put on there will be more than large enough. Even the old carb'd motors had alternators that would produce 45+ amps.
#5
TECH Senior Member
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IIRC.. the 70's era 10SI were maxed out at 48/63amp and the next generation were 12SI were 78/90amps. These newer generation of Alternators are 100/140amps..
If your worried about size.. you can try a Japanese Import Alternator.. they are small and can produce enough amps for your boat.
If your worried about size.. you can try a Japanese Import Alternator.. they are small and can produce enough amps for your boat.