To answer the question whether the alternator works correctly you just need to use any working instrument of appropriate measurement range, designed for measuring constant voltage and take a number of simple measurements.
We propose to follow the procedure described below:
Once the indicator light has gone off and the measured voltage is as required above, you may conclude the alternator is working correctly. If the voltage is not as required or the indicator light is still on, you may assume the alternator works incorrectly. If you want to try to diagnose the causes of alternator malfunction, it is worthwhile to perform additional procedures and take extra measurements:
Based on the measurements taken and indications of the indicator light you can tentatively identify the underlying cause of the alternator’s incorrect operation. This will help you make appropriate decisions and remove the defect. The table listing the symptoms versus their potential causes may prove helpful when diagnosing the problem.
Electromagnetic switches trigger connection between the starter motor and the battery when control voltage is applied from the ignition or the appropriate controller in the car. Because of the high current involved during the start-up, all elements in this high-current circuit must be carefully designed and well maintained. Insufficient quality of any single element causes additional drop in the voltage supplied to the starter motor and thus reduces power generated by the starter.
The switch contains two solid contacts and one moving contact. The moving contact is put in motion with a retractable core (so called plunger). In starters manufactured today, electromagnetic switches are frequently used in mechanical structures related to the so-called Bendix system.
How a starter electromagnetic switch works
Alternator is used in vehicles and Diesel engine-powered machines. It is an electric motor which transforms mechanical energy to electric current. Alternator is intended to ensure appropriate loading of the battery and supply power to the installed devices.
Starters are regularly modernised. They satisfy basic requirements to an ever higher degree and get more and more failure-free. Despite the typification tendency observed worldwide, there are several thousand different types of starters today. Frequently, the only difference between individual types comes down to geometrical parameters related to the method of mounting the starter in the engine.
Before you conclude that your starter is defective, eliminate any other causes which might affect its operation. Try the following procedure.
Never keep the starter working for more than 5 to 10 seconds. Repeat the attempts at intervals of several dozen seconds.