How many volts should a starter turn over?
You can test for proper cranking voltage with a voltmeter while—you guessed it—cranking the engine. The several hundred amperes of current the starter motor draws should pull the battery voltage down to a normal 9 to 10 volts.
How do you check a starter voltage drop?
To check the entire circuit, connect the meter positive lead to a clean spot on the starter motor case and the meter negative lead to the negative battery post. Crank the engine and note the reading. The voltage drop on the negative side should be 0.3 volts or less.
What does a voltage drop test?
Voltage Drop testing is a method of electrical diagnosis that can quickly locate high-resistance problems in a circuit. Increases in resistance increase the voltage drop. Whenever checking Voltage Drop, current must be flowing in the circuit. Each load device must receive its rated voltage to operate properly.
How to use voltage drop to troubleshoot the starter system?
Set your voltmeter to the lowest setting on the DC voltage scale. Connect your meter’s positive (red) lead to the starter motor case. Connect your meter’s negative (black) lead to the battery negative (-) post. Have an assistant turn the ignition key to the Start position to crank the engine for no more than 15 seconds.
Why do I get Low voltage on my starter battery?
You found pressure (voltage) bypassing the battery’s insulated plastic case through your meter. If your battery is really dirty and wet, try moving around one of the leads on the battery’s surface with the other lead still attached to either battery post. You will likely see very, very small voltage. Why?
How can I check the voltage of my starter?
Connect the meter’s positive (red) lead to the positive (+) post on the battery and the meter’s ground (black) lead to the starter battery terminal. Have an assistant crank the engine for a few seconds, but no more than 15 seconds: just enough to get an accurate voltage reading. Check your meter’s readout.
What should I do if my starter won’t turn?
If your engine’s starter actually won’t turn, or it turns slowly, then perfect! Nothing more to be done to disable the engine because you only need a few seconds to test for pressure. But if your engine starts within a second or two, you will need more time to do the voltage drop test.