Starter Motor - No-Load Test

WARNING: This page is about a different car, the 2007 Ford Pickup, 2007 Ford F550 Super Duty, 2007 Ford F450 Super Duty, and 2007 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

Connect a fully charged battery to the starter.
Connect the Alternator, Regulator, Battery and Starter Tester (ARBST) as illustrated.
Connect a remote starter switch between the starter solenoid Terminal S and the positive battery terminal post.
Press the remote starter switch. The pinion should shift to the crank position and the motor should run smoothly.
While the starter motor is running, record the voltmeter and ammeter readings.
The voltage reading should be greater than 11.0 volts and the amperage should be no more than 170 amps.

If voltage is lower than specified or amperage is higher than specified, refer to the results chart below to determine possible cause and corrective action.

STARTER MOTOR NO-LOAD TEST RESULTS

Test Result	Probable Source	Action to Take
Normal current and speed	Cranking motor OK	RECHECK the battery, switches and wiring, including voltage drop tests, if cranking motor operation on the engine is slow or sluggish.
Current flow with test circuit switch open	Solenoid contacts stuck closed	CARRY OUT the Starter Solenoid Component Test.
Failure to operate with very low or no current	Open solenoid winding	CARRY OUT the Starter Solenoid Component Test.
	Open field circuit	INSTALL a new starter motor.
	Open armature coil(s) or high insulation between commutator bars	INSTALL a new starter motor.
	Broken brush spring(s) or worn brushes	INSTALL a new starter motor.
Failure to operate with high current	Frozen bearing, or other damage to drivetrain	INSTALL a new starter motor.
	Direct ground in terminals or fields	INSTALL a new starter motor.
Low speed with high current	Excessive friction in bushings or gear reduction unit, bent armature shaft or loose pole shoe, bent driveshaft	INSTALL a new starter motor.
	Shorted armature	INSTALL a new starter motor.
	Grounded armature or fields	INSTALL a new starter motor.
Low speed with normal (or low) current	High internal electrical resistance caused by poor connections, defective leads or dirty commutator	INSTALL a new starter motor.
	Open solenoid winding	CARRY OUT the Starter Solenoid Component Test.
	Open field circuit	INSTALL a new starter motor.
	Broken brush spring(s) or worn brushes	INSTALL a new starter motor.
High speed with high current	Shorted fields	INSTALL a new starter motor.