Home Engine Systems Engine Parts Alternators Mercruiser 65 Amp Alternator (18-5960) Sierra International Mercruiser 65 Amp Alternator (18-5960) $386.39 Mercruiser 65 Amp Alternator (18-5960) quantity Add to cart Product Details Product Details For: Mercruiser. 65 amp. Serpentine pulley. Replaces: Mercruiser 807653T.