Truck kicked into power saving mode on way home from work, stopped by advanced, o'reilly, and autozone they all said bad alternator. Took to local mechanic said he couldnt find one anywhere has to be ordered 350+ tax in Denver from Emich Chevrolet 2-3 days. I called everyone I could find 1-2 week order. Ordered 200 amp midi generator fuse 7 bucks #74or75 arrived next day, installed. Now everything works after charge from Advanced but they still say alternator no good battery is overcharged and may blow if continues to over charge, Autozone now says it's within oem, o'reilly says good but bad voltage regulator. lol. Any thoughts/comments
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you probably need a new battery not an alternator....
Our truck have a really bad algorithm for maintaining the battery. Along with the ECM code that stops charging the battery under certain conditions. Like under hard acceleration.
it does that to lower the drag on the motor. It also over charg the battery when deceleration.
If conditions are met.
The problem is mainly with the absolute crap they have coded into the ECM for charging the battery.
Some times I check my battery voltage and the dic says 11 volts other times it says 15.5
One way to destroy a sealed battery is to charge it over 14.2
Maybe once or twice a year the voltage should come up to 15 volts to desolfate a wet cell battery. But never a GEL cell
Also a lead acid battery should never see a voltage lower than 12.5 volts. A lower voltage than 12.5 will shorten its life.
The idea of stopping the battery charge while under a load and charging while deceleration is a great idea. But GM has taken this to the extream.
These alternators do not have a built in regular, they use code in the ECU to control batTerry charging .
And it’s done really badly......