Starter No Load Test

Connect battery, alternator, regulator and starter motor tester as shown in Fig 1 . Turn tester load control knob to the extreme counterclockwise (decrease) position. Turn tester to voltmeter position. Crank engine, determine exact starter motor RPM using a mechanical tachometer, and record voltage.
Disconnect battery cable from starter motor. Turn load control knob clockwise (toward increase) until voltage is exactly the same as it was with battery connected to starter. Switch tester from voltmeter position to ammeter position and record amps.

If amperage at no load speed is below specification, the starter motor has high electrical resistance and should be repaired or replaced. If amperage is higher than specification and starter motor RPM is less than minimum RPM specified, disassemble, clean, inspect and test starter motor.

Fig 1: Starter No-Load Test Connections

Courtesy of FORD MOTOR CO.

STARTER NO LOAD TEST SPECIFICATIONS

Application

4" Frame

4 1/2" Frame

Voltage

12 Volts

Amperage

80 amps

67 amps.⁽¹⁾

RPM Range

6700 Min. RPM

7380-9356 RPM

⁽¹⁾	Specification is for American Motors. Ford Motor Company amperage is 85 amps.