{"product_id":"wai-21939n-alternator","title":"WAI 21939N Alternator","description":"\u003ch2\u003eAlternator for Ford Super Duty\u003c\/h2\u003e\u003cp\u003eThis WAI alternator is a 100% new replacement built for charging-system performance in heavy-duty applications. It delivers 175 amps and uses an internal regulator, making it a direct-fit option for Ford Super Duty trucks that need dependable electrical output.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e100% new alternator, not remanufactured\u003c\/li\u003e\n\u003cli\u003e175-amp output for higher electrical demand\u003c\/li\u003e\n\u003cli\u003eInternal regulator for integrated voltage control\u003c\/li\u003e\n\u003cli\u003eInternal fan design for compact packaging\u003c\/li\u003e\n\u003cli\u003eSerpentine pulley with 8 grooves included\u003c\/li\u003e\n\u003cli\u003eClockwise rotation with DENSO family design\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed Description\u003c\/h2\u003e\u003cp\u003eWAI builds this alternator with proprietary components and manufacturing processes to support long service life and consistent performance. The unit is configured with a pulley included, clockwise rotation, and a serpentine belt drive, which helps match the original charging-system layout on compatible Ford F-250 Super Duty, Ford F-350 Super Duty, Ford F-450 Super Duty, and Ford F-550 Super Duty applications. Part number 21939N is also cross-referenced to 21939 and 104211-0490 for the same application.\u003c\/p\u003e\u003cp\u003eThe DENSO family design and 175-amp rating make this alternator a practical replacement when the vehicle’s electrical system needs stable charging output for accessories and demanding operating conditions. Part number 21939N appears in Ford Super Duty fitments from 2017-2022, including F-250 Super Duty, F-350 Super Duty, F-450 Super Duty, and F-550 Super Duty models.\u003c\/p\u003e\u003ch2\u003eWhat It Helps Solve\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eLow charging output from a worn alternator\u003c\/li\u003e\n\u003cli\u003eBattery warning lights caused by charging-system faults\u003c\/li\u003e\n\u003cli\u003eVoltage instability under electrical load\u003c\/li\u003e\n\u003cli\u003eStarting issues related to insufficient alternator output\u003c\/li\u003e\n\u003cli\u003eAccessory performance problems from weak system charging\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eFits 2017-2022 Ford F-250 Super Duty, N\/A. Fits 2017-2022 Ford F-350 Super Duty, N\/A. Fits 2017-2022 Ford F-450 Super Duty, N\/A. Fits 2017-2022 Ford F-550 Super Duty, N\/A. Verify pulley style, belt type, rotation direction, and amperage rating against the original unit before installation. Confirm electrical connections and charging-system condition during replacement.\u003c\/p\u003e\u003ch2\u003eQuality Assurance\u003c\/h2\u003e\u003cp\u003eWAI states that this alternator is 100% new and manufactured with proprietary components and processes to support maximum life and performance.\u003c\/p\u003e","brand":"WAI","offers":[{"title":"Default Title","offer_id":53534285660341,"sku":"HGWL-21939N","price":238.37,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/WW_21939N_FRO.jpg?v=1792130149","url":"https:\/\/www.partcatalog.com\/products\/wai-21939n-alternator","provider":"PartCatalog","version":"1.0","type":"link"}