Starter Ground Circuit Test

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NOTE: Make all voltmeter connections at component terminal rather than at cable or wire end.

Disconnect inertia fuel shutoff switch. See COMPONENT LOCATIONS . Connect remote starter switch between starter solenoid terminal "S" (Yellow/Light Blue wire) and positive battery post. See Fig 1.

Fig 1: Testing Ground Voltage Drop
Courtesy of FORD MOTOR CO.
Using a digital voltmeter set at lowest voltage scale, connect positive voltmeter lead to starter housing, and negative lead to negative battery post. See Fig 1.
Engage remote starter switch while observing voltmeter. If voltmeter indicates .2 volt or less, circuit is okay. If voltmeter indicates more than .2 volt, clean negative cable connections at battery and engine. Retest ground circuit.
If voltage drop is still excessive, repair or replace negative battery cable and/or engine ground cable as necessary. Repeat starter circuit test after repair to ensure problem has been corrected.
If battery and cables test okay and starter motor still cranks slowly or not at all, install new starter motor.