Alternator upgrade help!!
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Teching In
Joined: May 2021
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Alternator upgrade help!! Been thinking about upgrading my stock 102 amp alternator to a 340 amp with a big 3 and with only a small system upgrade would that burn out my car electrical components ? Or would it be okay to run ?
TECH Addict
Joined: Oct 2016
Posts: 2,513
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From: PDX-OR-USA
This isa much hashed over topic, so you might search this forum a bit more first,,
340 is a lot of alternator... Welder or whooping big stereo?
The Alternator vendor should be the best source of info. There are a couple different option depending on engine year/origin etc.
340 is a lot of alternator... Welder or whooping big stereo?
The Alternator vendor should be the best source of info. There are a couple different option depending on engine year/origin etc.
TECH Fanatic
Joined: Dec 2017
Posts: 1,467
Likes: 265
From: Bossier City, Louisiana
Its the gauge of wiring in your vehicle leaving that gigantic alternator that worries me. Probably way too thin and undersized if you truly need that much power. The Big Three might not be enough.
Rick
Rick
Joined: Nov 2003
Posts: 11,328
Likes: 345
From: Jacksonville, FL (originally from Toronto Canada)
Alternators do not "push" current into the electrical system, they merely provide the current drawn by the various electrical components. For example, your turn signal bulb will pull about 2 amps while flashing regardless of whether you have a 102 amp alternator or a 340 amp alternator. The higher amperage alternator is only necessary when you add electrical circuits which will draw more current than the stock alternator can provide. That doesn't always mean huge stereos or other accessories - sometimes you just want more output at idle and a higher amperage alternator is the only way to get that.
So no, installing a huge alternator, by itself, will not cause any damage to your electrical system. But, as B52bombardier1 alluded, adding accessories which draw more current can overwhelm the factory wiring so you must ensure that you connect any high power accessories you install with large enough wire to handle the current draw. Also, make sure you install the appropriate size fuse in the circuit as close to the power source as possible. Remember, fuses are there to protect the wiring not the accessory... you want a fuse to blow before the current flow gets high enough to heat up the wire and possibly cause a fire.
So no, installing a huge alternator, by itself, will not cause any damage to your electrical system. But, as B52bombardier1 alluded, adding accessories which draw more current can overwhelm the factory wiring so you must ensure that you connect any high power accessories you install with large enough wire to handle the current draw. Also, make sure you install the appropriate size fuse in the circuit as close to the power source as possible. Remember, fuses are there to protect the wiring not the accessory... you want a fuse to blow before the current flow gets high enough to heat up the wire and possibly cause a fire.
