why dont battery keep a charge on 2006 Ford Freestyle

battery checked ok charging system says ok but alternator reads doides pass but low reg, .

by in Saint Henry, OH on April 09, 2011
1 answer
ANSWER by on April 09, 2011
Voltage regulator output should be above 14.0 Volts at 2,000 RPM engine speed. If it is not, this is your area of attention. Since the voltage regulator is internal to the alternator, you are likely going to need to replace the alternator.