Starter Motor No-Load Test Results

WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

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.
	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.