Are you thinking of buying a new starter because your engine won’t crank? Many starters are replaced unnecessarily and are later returned back to the auto-parts suppliers because they are presumed to be defective. When tested, there’s no fault found. The real problem is misdiagnosis. Professional technicians will usually make the correct diagnosis, but many semi technical mechanic are simply making a semi-educated guess – and they sometimes guess wrong.
One of the best ways to find out if your starter is bad is to have it “bench tested” at a parts store. If it cranks at normal rpm under load, the problem is something else and replacing the starter will definitely not fix the problem. If it fails to crank, the starter needs to be replaced.
When you buy a new or rebuilt starter, compare the old and new units to make sure the replacement starter is the correct one for your vehicle. Is the mounting surface and bolt configuration the same? Is the flywheel gear the same (count the teeth if you’re not sure).
BEFORE YOU CONTINUE READING ASK YOURSELF THESE QUESTIONS
What happens when you turn the key and try to start the engine?
If the answer is, “Nothing,” you should check the battery, battery terminals, battery cables and ignition circuit to make sure voltage is reaching the starter. If the battery is low or has corroded terminals or loose cable connections, the starter may not crank because of low voltage. If the solenoid that energizes the starter motor is faulty or has loose electrical connections, it will prevent the starter from cranking, too. A faulty ignition switch, park/neutral safety switch on the transmission linkage, clutch safety switch on the clutch pedal or a wiring problem are other faults that can also prevent a starter from cranking.
TYPES OF STARTERS
Starter motors come in several varieties. Most older vehicles have a rather large, heavy starter motor that has field coils around an armature. On newer vehicles, the size of the starter motor has been downsized either by using permanent magnets in place of field coils, or by using reduction gears to multiply the torque produced by a smaller motor. As a rule, permanent magnet and gear reduction starters are more expensive units to replace. Permanent magnet starters must also be handled with care because the magnets can be easily cracked and ruined if the starter is dropped on a hard surface. In the next post we will talk about common starter problems, types of alternator and CHARGING SYSTEM AND ALTERNATOR PROBLEM