NEW 12 VOLTS 110 AMPS ALTERNATOR FITS MERCRUISER 120 GM 2.5L 3-WIRE 1977-1989 20104 1100186 1102938 1102939 1103113 1103114 1103193 1105064 1105065 1105078 1105088 1105097 20115005TBA 18-5945