Hold-In Windings Test

If solenoid is not removed from starter motor assembly, disconnect field lead from terminal "M" on solenoid and insulate field lead from solenoid motor terminal. Connect an ammeter and switch in series with 12-volt battery and starter solenoid terminal "S" as illustrated. See Figure. Connect a voltmeter between solenoid terminal "S" and ground. Connect a carbon pile across battery.
Turn switch on and quickly adjust carbon pile load until voltage reads as specified. Check ammeter reading. Turn off carbon pile and open switch. On gasoline engines, at 10 volts reading should be 10-20 amps. On diesel engines, at 10 volts reading should be 12-14 amps. If amperage reading is not as specified, replace starter solenoid or starter assembly.