2009 Volkswagen Jetta Excess AC ripple

2009 VOLKSWAGEN JETTA
56,000 MILES • 2.5L • 5 CYL • FWD • AUTOMATIC
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ELECTRIC12
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  • 11 POSTS
Took my car to the dealer for a new battery. They performed a battery and charging system test. I have no warning dash lights or signs of a problem and drove it 900 miles since installing new battery.
Yet the dealer wants to sell me a new alternator. Service adviser wrote: "battery failed load test but also found excess ripple detected. Replaced battery as per customer concern to retest for bad alternator. Excess ripple is still present. Vehicle has proper charging voltage but excess ripple can cause alternator to overcharge battery and damage cell. Alternator needs replaced."
Does that make sense?
May 28, 2014 at 7:53 AM
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SATURNTECH9
  • ✓ASE Certified Mechanic
  • 30,869 POSTS
  • ASE Certified Mechanic
Yes it does you probably have a diode or rectifier the alternator produces ac volts which is converted to dc volts.Ac is more efficient to produce thats why they do that. Take it to auto zone and have them test the alternator they can check for the ac ripple.
May 28, 2014 at 12:41 PM
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