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.
