The 2005 started a new type of ECU alt control at idle the ecu only shoots for 12 volts depending on load , engine temps and batt temps etc
Low voltage warning wont come on till 11.8 , proper working voltage is only 12.8
Then there is a timer that allows low voltage at idle then after a given time voltage comes back this time can be as high as 255 seconds so be careful testing the alt at idle
If at idle the voltage does not look right but at higher idle (above 1800-2000) voltage is correct this would be normal
Now saying all this the Alt has the ability to charge as high as 14.69 depending on load , engine temps , rpm , batt temps etc
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