2001 Mercury Mariner 50-60HP Factory Service Manual, Page 107Get this manual
CHARGINGSTARTING SYSTEM
15 Ampere Stator
1Check battery voltage at battery with engine running2If battery voltage is above 14.5-15.0 volts, replace voltage regulatorrectifierCheck condition of battery as overcharging may have damaged battery3If battery voltage is below 14.5 volts, charge batteryIf battery can NOT be satisfactorily charged, replace battery4If battery accepts satisfactory charge, check battery voltage while cranking engineIf cranking voltage is not acceptable, replace battery5If cranking voltage is acceptable, disconnect the RED (voltage regulator) connector6Connect RED (+) ammeter lead to RED voltage regulator wire, and the BLACK () ammeter lead to the RED wiring harness wire7Secure starter wires away from flywheel8With engine running at the indicated RPM's, the ammeter should indicate the following appropriate amperes: 16 14 Alternator current (Amps) 12 10 RPM 1000 9A reading of 15 amperes at 5000 RPM indicates the charging system is functioning properly10If ammeter reads less than required amperes 5000 RPM, test the stator (refer to "Stator Ohms Test")If stator tests OK, replace rectifierregulator