Car starting system inspection tips

Checking the battery voltage:
You need to know whether you have enough juice to operate the starter motor by measuring the amount of voltage in your battery using a voltmeter.
1. Set your voltmeter to a range higher than battery voltage, like 20 volts on the DC (direct current) voltage scale.
2. Turn on the meter and connect the test leads across the battery terminals. Touch the negative lead to the negative (-) post on the battery and the positive lead to the positive (+) post on the battery.
3. Turn on your car’s headlights.
4. Read the display on your meter. Your battery should have between 12.4V (75% charge) and 12.6V (100% charge) to properly operate the starter motor. If there’s less than 12.4V, recharge the battery and try to start the engine again.
With a reading of 12.4V or less on a three to four years old battery, it’s a good idea to hydrometer-check your battery. The hydrometer is a simple tool that lets you know the state of charge and health of your battery. So you’ll know whether one or more cells have failed. You could purchase an hydrometer and then check  articles on troubleshooting a car battery using a hydrometer. Alternatively have your vehicle checked at an authorised auto dealer or mechanic.

Inspecting cables and wires:
Corrosion around battery terminals prevents electrical flow. This is a common problem on a battery or starter system that hasn’t received much attention. If you notice a layer of corrosion around one or both battery terminals clean them with a solution of baking soda and warm water.
* Mix 237 ml of warm water for 1 tablespoon of baking soda in a small container.
* Thoroughly mix the solution.
* Disconnect the terminals from the battery and apply the solution to the terminals and battery posts using a soft brush.
* Clean the battery top with the solution as well to remove dirt and acid which drains battery power, but don’t let the cleaning solution seep under the filler caps.
* Remove the caps from the top of the battery and check the electrolyte level. The electrolyte should reach the bottom of the filler rings. If necessary add distilled water to bring the electrolyte to the correct level.
* Check the tray where the battery sits and clean it as well.
* Reconnect the terminals and try starting the engine again.

Inspecting the starter solenoid:

Check the connections at the starter solenoid (the small cylinder on top of the starter) or starter relay. The positive (red) battery cable connects directly to the solenoid or starter relay. Can’t find the relay? Consult the vehicle repair manual for your particular car make and model.

If the solenoid or relay fails, the car won’t start.
* To quickly check the solenoid, disable the starting system by disconnecting the thick wire from the center of the distributor cap or by removing the fuel pump fuse — consult your vehicle repair manual to locate the fuse if necessary. This will prevent the engine from accidentally starting as you check the solenoid or starter relay.
* If you disconnected the wire from the distributor, ground it to a bolt or unpainted metal bracket on the engine block using a jumper wire.
* Ask an assistant to try starting the engine as you listen for any sounds coming from the starter solenoid or relay. If you hear a solid and loud click, it means the electrical current is reaching the solenoid and it’s properly working. If you hear a weak click or chattering sound, check the wires connected to the starter solenoid or relay.

Check for dirty, loose, disconnected or broken wires that will prevent electrical current from reaching the motor. If the wires and connections are in good condition, the starter motor, solenoid or relay have failed, and you need to replace it.

Checking the starter motor:
Depending on your particular vehicle model you may need to raise the front of the car or remove the intake manifold or some other component to reach the starter motor. Consult the car repair manual for your particular model if necessary.
* If you need to raise your car, safely support it on jack stands, engage the parking brake and block the wheels to prevent the car from rolling.
* Make sure the starter mounting bolts are tight. Loose mounting bolts will keep the starter drive from properly engaging the flywheel. When this happens, you’ll hear a grinding noise as you try to fire up the engine, since the ring gear on the flywheel and the pinion gear on the starter clash, unable to mesh properly.
* If the mounting bolts are tight, remove the starter motor from the vehicle and check the pinion gear — this is the small gear at the front of the starter that engages the flywheel to crank the engine. Check the condition of the pinion gear’s teeth. Worn or damaged gear teeth will prevent you from cranking the engine as well.
* Using a standard screwdriver, try to rotate the pinion gear in both directions. The gear should only rotate in one direction. If it moves in both directions or doesn’t move at all, replace the starter.

Inspecting the engine flywheel:
If you removed the starter motor for inspection it’s a good idea to check the flywheel as well. The flywheel is the large, heavy wheel between the engine and transmission. This is the wheel that the starter pinion gear engages to crank the engine.
* Once you’ve removed the starter motor set your transmission to Neutral.
* Have an assistant rotate the crankshaft by turning the center bolt on the crankshaft pulley using a ratchet or breaker bar and a socket. You’ll find this pulley at the front and bottom of the engine block. This pulley rotates the drive or serpentine belt to run the alternator, steering pump and other components. Depending on your vehicle model you may need to remove a wheel to gain access to the pulley center bolt.
* Watch the flywheel as it rotates and make sure the teeth are in good condition. Missing or damaged teeth will prevent the starter motor from cranking the engine. Replace the flywheel, if necessary.