Understanding GM late model alternator function.

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Doubeleive

Wes
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I went thru a lot of this troubleshooting when I was having issue's with the RVC and I determined it to be the battery in the end, battery passed testing (barely) but it was enough to cause a low state of charge all the time, new battery resolved the issue. With the way I drive i rarely see "economy mode" lol. I think I have seen it once in the last 2 years.
 

tom3

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I've seen the economy mode several times on our journeys. Didn't realize it had the potential of a 1 mpg add. But just had a new battery, big Delco, put in and seeing pretty constant high voltage, 14.7 to 15.2, most of the time. His mention of his new battery being junk sure rings a bell. Maybe take it back for a battery test procedure?
 

Doubeleive

Wes
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I've seen the economy mode several times on our journeys. Didn't realize it had the potential of a 1 mpg add. But just had a new battery, big Delco, put in and seeing pretty constant high voltage, 14.7 to 15.2, most of the time. His mention of his new battery being junk sure rings a bell. Maybe take it back for a battery test procedure?
it's like he said if everything checks out good then it's usually poor ground or the battery, mine gave me fits because of the battery it wouldn't go into various modes even though the battery seemed ok, I could turn on everything and still only have 11v output
 

gapost

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Yeah, first long trip with my 19 Tahoe and I saw the voltage drop on the gauge. Thought my alternator was going bad LOL.
 

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