Can a alternator test good and still be bad?
Can a alternator test good and still be bad?
The only way to know if an alternator is good or bad is to bench test it on an alternator test stand. Charging output can be tested on a vehicle with a digital voltmeter. If an alternator can produce normal voltage and current during a bench test, the problem is not the alternator but something else on the vehicle.
Can a car battery be used as an alternator?
That’s battery cable trick. When cars had generators you could test the generator by running the car with the battery disconnected. It’s different with an alternator and with todays cars. You can spike the electronics very easily. The battery is not just to start the car, it is also acts as a big capacitor to eliminate and absorb those spikes.
What does the battery light on the alternator mean?
This is the same connector that lets the on-board computer know if the alternator is charging or not, which is what the battery light actually means. You can use a volt meter to test what the battery is receiving by connecting it to the middle of the posts while the engine is running.
What should the resistance be for an alternator?
If all this checks out then I suspect you have a wiring issue. I would perform either a voltage drop or resistance measurement of each of the wires from the PCM to the alternator. Also, through the fusible link from the battery to the alternator. You should have less then a half ohm of resistance.
Is the alternator good in a 2002 Dakota Durango?
Battery good, Alternator Good, gauge shows low voltage. I have a 2002 4.7 Dak with 118k miles, never replaced anything besides battery and oil changes. Never have had any problems until now. It started with my check gauges light coming on and I noticed my battery gauge went all the way to the L.
What should the voltage of an alternator be?
Connect the other lead to a good ground (the negative post on the battery is a great choice!). Your alternator should be putting out between 13.5 to 15 volts. Anything less than this, and you have a bad alternator! If your alternator is putting out this voltage, then something else is killing your battery.
Can a bad alternator kill a good battery?
Bad alternators can absolutely kill a good battery. There are two ways that it can do this. First, your alternator might not shut off and end up overloading the battery with too much voltage. Conversely, it might not charge the battery at all.
This is the same connector that lets the on-board computer know if the alternator is charging or not, which is what the battery light actually means. You can use a volt meter to test what the battery is receiving by connecting it to the middle of the posts while the engine is running.
What can I do if my car battery keeps dying?
To check cold-cranking amps, you need a specialty tool. The good news is that you can take your car to AutoZone and they will test and charge your battery for free. Check the alternator. Yes, you think it’s okay, but did you check it the right way?
