Starting System Testing and Repair
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A starting system is easier to work on than the car’s other electrical systems. It only has about five major components that cause problems.
Common starting system problems
In a no crank-problem, the engine crankshaft does NOT rotate properly with the ignition key at start. The most common causes are a dead battery, poor electrical connection, or faulty system component.
A slow cranking condition occurs when the engine crankshaft rotates at lower than normal speed. It is usually caused by the same kind of faults producing a no-crank problem.
A buzzing or clicking sound from the solenoid, without cranking, is commonly due to a discharged battery or poor battery cable connections. Low current flow is causing the solenoid plunger to rapidly kick in and out, making a clattering sound.
A single click sound, without cranking, may point to a bad starting motor, burned solenoid contacts, dead battery, or engine mechanical problems. The click is usually the solenoid closing or the pinion gear contacting the flywheel gear.
A humming sound, after momentary engine cranking, may be due to a bad starter overrunning clutch or pinion gear unit. Pinion gear wear can make the gear disengage from the flywheel gear too soon. This can let the motor armature spin rapidly, with a humming sound.
A metallic grinding noise may be caused by broken flywheel teeth wear. The grinding may be the gears clashing against each other.
Normal cranking, without starting, is usually NOT caused by the starting system. There may be trouble in the fuel or ignition systems. With a diesel engine, check engine speed. If cranking rmp is low. The diesel may not start.
Sometimes the starting solenoid feeds current to the ignition system after engine starting. If the engine starts and then dies (stop running) as the ignition key is released, check voltage from the solenoid to the ignition system. You could have an open wire or connection in the solenoid circuit. A defective ignition switch or writing problem are other possible causes.
Starting headlight test
A starting headlight test will quickly indicate the causes of trouble in a starting system. Turn the headlights ON and try to start the engine. NOTE any sounds and watch the brightness of the headlights.
Greg Lorson
http://greglorson.weebly.com
A starting system is easier to work on than the car’s other electrical systems. It only has about five major components that cause problems.
Common starting system problems
In a no crank-problem, the engine crankshaft does NOT rotate properly with the ignition key at start. The most common causes are a dead battery, poor electrical connection, or faulty system component.
A slow cranking condition occurs when the engine crankshaft rotates at lower than normal speed. It is usually caused by the same kind of faults producing a no-crank problem.
A buzzing or clicking sound from the solenoid, without cranking, is commonly due to a discharged battery or poor battery cable connections. Low current flow is causing the solenoid plunger to rapidly kick in and out, making a clattering sound.
A single click sound, without cranking, may point to a bad starting motor, burned solenoid contacts, dead battery, or engine mechanical problems. The click is usually the solenoid closing or the pinion gear contacting the flywheel gear.
A humming sound, after momentary engine cranking, may be due to a bad starter overrunning clutch or pinion gear unit. Pinion gear wear can make the gear disengage from the flywheel gear too soon. This can let the motor armature spin rapidly, with a humming sound.
A metallic grinding noise may be caused by broken flywheel teeth wear. The grinding may be the gears clashing against each other.
Normal cranking, without starting, is usually NOT caused by the starting system. There may be trouble in the fuel or ignition systems. With a diesel engine, check engine speed. If cranking rmp is low. The diesel may not start.
Sometimes the starting solenoid feeds current to the ignition system after engine starting. If the engine starts and then dies (stop running) as the ignition key is released, check voltage from the solenoid to the ignition system. You could have an open wire or connection in the solenoid circuit. A defective ignition switch or writing problem are other possible causes.
Starting headlight test
A starting headlight test will quickly indicate the causes of trouble in a starting system. Turn the headlights ON and try to start the engine. NOTE any sounds and watch the brightness of the headlights.
Greg Lorson
http://greglorson.weebly.com