A voltmeter will show you how much voltage is currently passing through the circuit the meter is a part of.  Start by attaching the positive lead (red) from the voltmeter to the positive terminal on the battery.  The positive terminal will be labeled with the letters “POS” or the positive (+) symbol. Some volt meters may clip into place, while others may require you to hold to lead onto the battery. This test is to determine how much voltage the starter solenoid is drawing from the battery when it is attempting to start.  Place the negative lead (black) from the voltmeter on the negative terminal on the battery to complete the circuit. With the positive and negative leads connected to the battery, the voltmeter should turn on. Your car battery should produce approximately 12 volts when nothing is drawing off of it.  Read the display on the volt meter to ensure your battery is producing an adequate level of power.  If the voltmeter reads less than 12 volts, the vehicle may not be starting due to insufficient charge on the battery. The number may jump around as you move the leads a bit and the meter tries to read the voltage.  Wait for it to settle to determine the baseline voltage. While holding the leads on the positive and negative terminals on the battery, have a friend turn the key in the ignition to attempt to start the vehicle.   Be careful to stay clear of anything that may move if the engine actually starts.  The voltage reading from the battery should drop approximately half a volt while the starter attempts to start the vehicle. If the voltage does not drop, there is an issue with the connection from the battery to the starter. Place the positive lead from the voltmeter on lower terminal from the solenoid (closer to the starter).  Then place the negative lead on the upper most terminal coming from the battery.  Have your friend turn the key again. Ensure the leads are firmly touching or attached to the terminals coming from the solenoid for a good reading. The voltage drop you see on the solenoid should match the drop you saw on the battery.  The drop in voltage should not exceed a half a volt.  If you do not read any voltage at all, the solenoid needs to be replaced.  If the voltage drops less than a half a volt, there is an issue inside the solenoid. If the voltage drops too much, there may be a fault somewhere in the connection, such as a crimped line from the battery to the solenoid.
وصِّل مقياس فرق الجهد بالطرف الموجب من البطارية. وصّل الطرف السالب بالطرف الأرضي. لاحظ قراءة مقياس فرق الجهد. اطلب من صديق تحريك مفتاح التشغيل. حرّك مقياس فرق الجهد إلى أطراف ملف بادئ التشغيل اللولبي. راقب حدوث انخفاض في فرق الجهد.