Easy step by step guide on how to repair an automotive engine that will not crank
over (starter will not work), steps are presented in order of popularity, this article
pertains to most vehicles.
Difficulty Scale: 4 of 10
Begin with the vehicle on level ground, in park with the emergency brake set.
- Check for terminal/cable corrosion or
loose cables, terminal or cable corrosion can hinder electrical flow not allowing
the starter to pull a sufficient amount of amperage/voltage.
Step 2 - Check the battery for proper voltage,
low voltage will also cause the starter solenoid to not engage or engage and disengage
rapidly which creates a machine gun sound. A starter motor must operate on a sufficient
flow of electrical power, the battery must be in good working order to supply this
Clean Battery Cable Ends
Step 3 - Use a test light to inspect PDC (power
distribution center) starter system fuses and replace as needed.
Step 4 - Use a
attached to ground, have a helper turn the key to the start position
while testing the small trigger wire on the starter solenoid, it should light up,
next test the large power terminal which should also have power (light up). If both
terminals have power the starter has failed and replacement is required. (Note:
Use caution when testing as to not connect the test light probe to ground while
checking for power.)
Step 5 - If there was no power observed at the
small trigger wire of the starter solenoid, a malfunction in the starter trigger
system is not allowing electrical flow. Most vehicles have a security system which
is built into the starting system, sometimes the system will simply become confused
due to a glitch. If the security light is flashing while the starter is being engaged
the system is malfunctioning. First, try to lock all doors of the vehicle and wait
ten minutes, then unlock the doors and try to start the engine. The next step is
to disconnect the battery for ten minutes, and reconnect to retry. Also, the frequency
chip located inside the ignition key can be a problem, test this problem using a
Start Motor Trigger and Power Wire
Step 6 - The
is designed to stop the starter from operating while the automatic
transmission is in drive, or reverse. If this switch malfunctions it will cause
the starter to not engage.
- The clutch pedal position sensor is used
to stop the starter from operating while the transmission is in gear, if this switch
fails or becomes maladjusted the starter while not operate.
be in good working order for the engine to start. Malfunctions such as a blown head
gasket or other internal failures can cause the starter not to operate.
There are some easy fixes that are attributed to this problem, one is that the
gear selector has not been pushed fully into park (automatic transmission) or the
clutch is not fully depressed (standard transmission.) Also, some vehicles need
to have the brake pedal depressed before the starter will operate. A starter is
designed with a bendix which engages into the flywheel to crank the engine over.
If this bendix fails it will allow the starter motor to turn, but not engage. When
this condition occurs the starter will "freewheel", allowing the starter motor to
turn without engaging into the flywheel.
An engine flywheel/flex plate is used to work with the starter and is connected
to the engine crankshaft. If this part fails, the starter will operate, but the
engine will not crank over. Disassembly is required to inspect for the condition.
Usually this problem is accompanied by a strange noise while the starter is operating.
Tools and Supplies Needed
- Wrench set
- Socket set
- Voltmeter or test light
- Battery terminal cleaner
- Protective eyewear and gloves
Article first published 2016-02-04