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Q: I can't find the right alternator for my Mercedes-Benz. 2003 Mercedes SL500

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I have spent the past week, and gone to at least 50 websites looking for the correct alternator for my Mercedes-Benz. All the alternators I've found are 12 volts 150 AMP. The original alternator i brought out of the engine, which i'm currently looking to change, is 14 volts and 150 AMP. This alternator came with the car. Please do you know a website where i can buy a 14 volt 150 AMP alternator that fits a 2003 Mercedes-Benz SL500? Please include direct link to the webpage. (if there's any.) My car has an automatic transmission.

Hello - any of the MB parts sites selling a "12v, 150 amp" alternator that fits your SL500 is selling the correct specification alternator. Your cars electrical system is nominally 12 volts. The voltage regulator within the alternator allows the alternator to charge at up to 14 volts in order to bring the battery back up to at least 12 volts. While cranking for example, system voltage can drop to 10 volts or so. The difference in "system voltage vs charging voltage" is a bit confusing, but hopefully, this has helped your understanding. If not, shoot any other questions our way.

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