150 amps not enough?

ItstheHOFF

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My alternator is going bad. Everything electronic keeps shutting off with the engine running. Chevy dealer says some have 150, some have 170. I asked if 170 would be better, and they said it depends if my battery can handle it. Rockauto says a higher amp alternator could actually save you fuel. Would fuses might get blown over 20 amps?? What would y’all recommend?
 

exp500

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Different configuration trucks take different alternators. Get the number off your existing alt and g??gle it. Will save you a fair amount. Rockauto good too.
 

Bill 1960

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The battery is built to handle cranking amps. Another potential 20 charging is a meaningless difference. I’d get the PN from mine and buy the same again unless there’s some heavy electrical demand which hasn’t been mentioned.
 

Doubeleive

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it really doesn't matter, nor will it hurt anything in these truck to run a stock alternator or a higher amperage unit, if you have more electronics then a higher amperage unit helps things run smoother, no flickering things like that, you do not have to worry about fuses or wires burning up, a thicker gauge alternator wire can help as well, some people add more grounds. generally lower amperage alternators are put in the 1500's but the 2500's 3500's will come with a 160-245a simply because they may have more lights or accessories being used, the wiring and fuses are the same essentially. These trucks have RVC (regulated voltage control) so it's only going to use what it needs anyway.
 

iamdub

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My alternator is going bad. Everything electronic keeps shutting off with the engine running. Chevy dealer says some have 150, some have 170. I asked if 170 would be better, and they said it depends if my battery can handle it. Rockauto says a higher amp alternator could actually save you fuel. Would fuses might get blown over 20 amps?? What would y’all recommend?

"If your battery can handle it"? You mean they're concerned about an extra 20 amps of available power going into the box of lead plates and acid that provides 700+ amps?

It doesn't work that way. The amperage an alternator puts out doesn't mean it's "shooting out" that many amps. It just means that it can push up to that amount should the load ("load" is the battery and everything electrical on the vehicle) on it pull it while maintaining its design voltage. Same with the battery- it can provide up to 700, 900, or 1,100 amps (whatever the battery is rated at) should the load pull it, such as a starter trying to turn over a frozen engine. Ever seen someone put a handheld digital volt meter on the terminals of a battery to test the voltage? That small, solid state electronic device didn't absorb 700 amps or more of power. You can stick a tiny LED bulb to that battery and it'll light up, running on 12 volts and drawing a mere fraction of an amp. The battery and alternator are similar in this aspect. With a small load such as an LED bulb or even factory halogen headlights, they won't even feel it. With a larger load such as starter (a vehicles highest load), they "feel" it enough that the voltage drops a little.

Being that the charging of these alternators is controlled by the PCM so that it isn't charging when not needed, that part could save you fuel. It's nothing you'd ever be able to realize or even calculate do to the other, overshadowing factors. I'd be satisfied by the reduced wear on the alternator than the supposed fuel-saving aspect.

If you can get a plug-and-play 170A alternator and the price is worth it to you, then go for it.
 

ItstheHOFF

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Battery went bad today. Could have been old, could have been the heat. Just curious it went out so soon after replacing the alternator.
 

Doubeleive

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Battery went bad today. Could have been old, could have been the heat. Just curious it went out so soon after replacing the alternator.
the battery was probably the original issue, rather than the alternator, usually battery's take a bow out with the change of seasons or hot weather. They barely make it past warranty here in Cali, sometimes sooner.
 

drakon543

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a weak battery can severely tax an alternator so replacing both isn't uncommon. as above stated the alternator output is controlled it doesn't constantly output its maximum ability. im unsure if your truck has an amp gauge but if you jump a vehicle you can see the gauge increase as more demand is connected. just a common thing mosy people have done you should understand.
 

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