It depends on which diode, but sometimes it can.
the right answer
The diode is neither shorted nor open. It is a zener diode and it is conducting in both directions. If it were truly shorted, it would read closer to zero ohms in both directions.
Yes. If the alternator is dead and you drive the vehicle, all the power is coming from the battery and it will eventually drain completely. Also, if a diode is shorted inside the alternator, that can drain a battery.
No a diode will not work when the ignition key is off.
due to high voltage across the diode ie more than piv of the diode or current flows more than maximum allowed range of diode.
If Your Battery Is being drained Dont Just Assume It is A Short .....:) It Could be The diode In your Atlenater That Has Went bad A Diode Is Like a Water valve it Only Lets Current Flow One direction But if it goesa Bad that it Will Let The Current Drain From the battery .....:)
There are 3 possibilities: either the battery is going bad, a device is being left on in the car (lights, etc) or an alternator diode is shorted.
Try disconnecting the alternator, could be the diode pack
Check that alternator is charging battery properly and change battery to see if you still getting same issues. It can also be a leak in your car radio, burnt alternator diode, or a shorted coil in the central locking system or windows.
Mine did that. Check voltage regulator. There is a small diode shorted inside. Replace regulator, about $26 from Napa.
It depends on how the diode is damaged. There are generally two cases. One, the diode is shorted, and conducts with a low impedance in both directions. The other, the diode is open, and does not conduct, having a high impedance, in both directions. The effect depends on the particular circuit. In a power supply, a shorted diode will often blow the fuse, while an open diode will result in no output, or in high ripple voltage output. Is it possible that diode has normal voltage output but wrong current,meaning low mA?
A: A very low reading in both direction will indicate a shorted diode. A meter is an indicator not a tester keep that in mind
Bad diodes in the alternator can cause the battery to go dead when the car is off. The diode bridge (six diodes) is directly connected to the battery, and is used to convert three phase delta AC from the alternator's stator to DC for the battery. Normally, if the engine is not running, the diodes are reverse biased and do not conduct current. If one of the high side diodes is shorted then the diode trio (another set of three diodes supplying the regulator/rotor) could conduct and drain the battery. Often, a diode failure is a short or an open. A short in a high side diode along with a short in a low side diode would result in high current from the battery, and that would probably blow the fusible link. An open would result in poor performance of the alternator.
With a 10mA forward bias current, if the voltages at the anode and cathode of a diode in a circuit are found to be the same, then the diode most likely to be shorted.
A: Nobody can answer that. It depends on the diode, battery on the meter, scale of the meter. It should never read zero or close to zero ohms and reversing the lead it should just be close to open but it may read some hi k ohms. A meter test is just to find shorted diodes and extremely leaking diode.
When the polarity of the battery is such that electrons are allowed to flow through the diode,then the diode is said to be forward-biased. Conversely, when the battery is "backward" and the diode blocks current, then the diode is said to be reverse-biased. A diode may be thought of as like a switch: "closed" when forward-biased and "open" when reverse-biased.
There must be a break in the power supply elsewhere in the circuit. I suggest a blown fuse The only diode that generates electricity is a solar cell
when the positive terminal of the battery is connected to the anode and negative terminal of the battery is connected to cathode then the diode is in forward bias
battery +ive ----> volteter +ive voltmeter +ive ----> diode +ive diode -ive ----> ammeter +ive ammeter -ive ----> voltmeter -ive voltmeter -ive ----> battery -ive
the power suppy diode are probably shorted.
The most straightforward and unbiased way is to remove the diode from the circuit and check it with a diode tester. Alternatively, if the diode is shorted, the bridged will measure shorted. If it is open, running the generator and monitoring the output with an oscilloscope will reveal a missing phase. One example of an open diode problem in an automobile alternator application is that the alternator will put out enough current to keep the system fail light off, but not put out enough current to meet rated output load.
a: the reading will be the same both ways a: A shorted diode will exhibit the same voltage, nearly zero, across it. (Normally, it has between 0.6 and 1.7 volts across it in the forward bias condition.) Out of circuit, measured with an ohmmeter, it will show near zero ohms in both directions.